diff --git a/src/borg/archive.py b/src/borg/archive.py
index 7a4d7e877..09a3d3f70 100644
--- a/src/borg/archive.py
+++ b/src/borg/archive.py
@@ -35,7 +35,7 @@ from .helpers import ProgressIndicatorPercent, log_multi
 from .helpers import PathPrefixPattern, FnmatchPattern
 from .helpers import consume
 from .helpers import CompressionDecider1, CompressionDecider2, CompressionSpec
-from .item import Item
+from .item import Item, ArchiveItem
 from .key import key_factory
 from .platform import acl_get, acl_set, set_flags, get_flags, swidth
 from .remote import cache_if_remote
@@ -269,37 +269,36 @@ class Archive:
                     break
                 i += 1
         else:
-            if name not in self.manifest.archives:
+            info = self.manifest.archives.get(name)
+            if info is None:
                 raise self.DoesNotExist(name)
-            info = self.manifest.archives[name]
-            self.load(info[b'id'])
+            self.load(info.id)
             self.zeros = b'\0' * (1 << chunker_params[1])
 
     def _load_meta(self, id):
         _, data = self.key.decrypt(id, self.repository.get(id))
-        metadata = msgpack.unpackb(data)
-        if metadata[b'version'] != 1:
+        metadata = ArchiveItem(internal_dict=msgpack.unpackb(data))
+        if metadata.version != 1:
             raise Exception('Unknown archive metadata version')
         return metadata
 
     def load(self, id):
         self.id = id
         self.metadata = self._load_meta(self.id)
-        decode_dict(self.metadata, ARCHIVE_TEXT_KEYS)
-        self.metadata[b'cmdline'] = [safe_decode(arg) for arg in self.metadata[b'cmdline']]
-        self.name = self.metadata[b'name']
+        self.metadata.cmdline = [safe_decode(arg) for arg in self.metadata.cmdline]
+        self.name = self.metadata.name
 
     @property
     def ts(self):
         """Timestamp of archive creation (start) in UTC"""
-        ts = self.metadata[b'time']
+        ts = self.metadata.time
         return parse_timestamp(ts)
 
     @property
     def ts_end(self):
         """Timestamp of archive creation (end) in UTC"""
         # fall back to time if there is no time_end present in metadata
-        ts = self.metadata.get(b'time_end') or self.metadata[b'time']
+        ts = self.metadata.get('time_end') or self.metadata.time
         return parse_timestamp(ts)
 
     @property
@@ -336,7 +335,7 @@ Number of files: {0.stats.nfiles}'''.format(
         return filter(item) if filter else True
 
     def iter_items(self, filter=None, preload=False):
-        for item in self.pipeline.unpack_many(self.metadata[b'items'], preload=preload,
+        for item in self.pipeline.unpack_many(self.metadata.items, preload=preload,
                                               filter=lambda item: self.item_filter(item, filter)):
             yield item
 
@@ -366,7 +365,7 @@ Number of files: {0.stats.nfiles}'''.format(
         metadata = {
             'version': 1,
             'name': name,
-            'comment': comment,
+            'comment': comment or '',
             'items': self.items_buffer.chunks,
             'cmdline': sys.argv,
             'hostname': socket.gethostname(),
@@ -376,10 +375,11 @@ Number of files: {0.stats.nfiles}'''.format(
             'chunker_params': self.chunker_params,
         }
         metadata.update(additional_metadata or {})
-        data = msgpack.packb(StableDict(metadata), unicode_errors='surrogateescape')
+        metadata = ArchiveItem(metadata)
+        data = msgpack.packb(metadata.as_dict(), unicode_errors='surrogateescape')
         self.id = self.key.id_hash(data)
         self.cache.add_chunk(self.id, Chunk(data), self.stats)
-        self.manifest.archives[name] = {'id': self.id, 'time': metadata['time']}
+        self.manifest.archives[name] = (self.id, metadata.time)
         self.manifest.write()
         self.repository.commit()
         self.cache.commit()
@@ -400,7 +400,7 @@ Number of files: {0.stats.nfiles}'''.format(
         cache.begin_txn()
         stats = Statistics()
         add(self.id)
-        for id, chunk in zip(self.metadata[b'items'], self.repository.get_many(self.metadata[b'items'])):
+        for id, chunk in zip(self.metadata.items, self.repository.get_many(self.metadata.items)):
             add(id)
             _, data = self.key.decrypt(id, chunk)
             unpacker.feed(data)
@@ -588,12 +588,12 @@ Number of files: {0.stats.nfiles}'''.format(
                     raise
 
     def set_meta(self, key, value):
-        metadata = StableDict(self._load_meta(self.id))
-        metadata[key] = value
-        data = msgpack.packb(metadata, unicode_errors='surrogateescape')
+        metadata = self._load_meta(self.id)
+        setattr(metadata, key, value)
+        data = msgpack.packb(metadata.as_dict(), unicode_errors='surrogateescape')
         new_id = self.key.id_hash(data)
         self.cache.add_chunk(new_id, Chunk(data), self.stats)
-        self.manifest.archives[self.name] = {'id': new_id, 'time': metadata[b'time']}
+        self.manifest.archives[self.name] = (new_id, metadata.time)
         self.cache.chunk_decref(self.id, self.stats)
         self.id = new_id
 
@@ -602,7 +602,7 @@ Number of files: {0.stats.nfiles}'''.format(
             raise self.AlreadyExists(name)
         oldname = self.name
         self.name = name
-        self.set_meta(b'name', name)
+        self.set_meta('name', name)
         del self.manifest.archives[oldname]
 
     def delete(self, stats, progress=False, forced=False):
@@ -625,7 +625,7 @@ Number of files: {0.stats.nfiles}'''.format(
         error = False
         try:
             unpacker = msgpack.Unpacker(use_list=False)
-            items_ids = self.metadata[b'items']
+            items_ids = self.metadata.items
             pi = ProgressIndicatorPercent(total=len(items_ids), msg="Decrementing references %3.0f%%", same_line=True)
             for (i, (items_id, data)) in enumerate(zip(items_ids, self.repository.get_many(items_ids))):
                 if progress:
@@ -844,7 +844,7 @@ Number of files: {0.stats.nfiles}'''.format(
     @staticmethod
     def list_archives(repository, key, manifest, cache=None):
         # expensive! see also Manifest.list_archive_infos.
-        for name, info in manifest.archives.items():
+        for name in manifest.archives:
             yield Archive(repository, key, manifest, name, cache=cache)
 
     @staticmethod
@@ -1075,8 +1075,9 @@ class ArchiveChecker:
             except (TypeError, ValueError, StopIteration):
                 continue
             if valid_archive(archive):
-                logger.info('Found archive %s', archive[b'name'].decode('utf-8'))
-                manifest.archives[archive[b'name'].decode('utf-8')] = {b'id': chunk_id, b'time': archive[b'time']}
+                archive = ArchiveItem(internal_dict=archive)
+                logger.info('Found archive %s', archive.name)
+                manifest.archives[archive.name] = (chunk_id, archive.time)
         logger.info('Manifest rebuild complete.')
         return manifest
 
@@ -1187,7 +1188,7 @@ class ArchiveChecker:
                 return required_item_keys.issubset(keys) and keys.issubset(item_keys)
 
             i = 0
-            for state, items in groupby(archive[b'items'], missing_chunk_detector):
+            for state, items in groupby(archive.items, missing_chunk_detector):
                 items = list(items)
                 if state % 2:
                     for chunk_id in items:
@@ -1215,37 +1216,38 @@ class ArchiveChecker:
 
         if archive is None:
             # we need last N or all archives
-            archive_items = sorted(self.manifest.archives.items(), reverse=True,
-                                   key=lambda name_info: name_info[1][b'time'])
+            archive_infos = self.manifest.archives.list(sort_by='ts', reverse=True)
             if prefix is not None:
-                archive_items = [item for item in archive_items if item[0].startswith(prefix)]
-            num_archives = len(archive_items)
+                archive_infos = [info for info in archive_infos if info.name.startswith(prefix)]
+            num_archives = len(archive_infos)
             end = None if last is None else min(num_archives, last)
         else:
             # we only want one specific archive
-            archive_items = [item for item in self.manifest.archives.items() if item[0] == archive]
-            if not archive_items:
+            info = self.manifest.archives.get(archive)
+            if info is None:
                 logger.error("Archive '%s' not found.", archive)
+                archive_infos = []
+            else:
+                archive_infos = [info]
             num_archives = 1
             end = 1
 
         with cache_if_remote(self.repository) as repository:
-            for i, (name, info) in enumerate(archive_items[:end]):
-                logger.info('Analyzing archive {} ({}/{})'.format(name, num_archives - i, num_archives))
-                archive_id = info[b'id']
+            for i, info in enumerate(archive_infos[:end]):
+                logger.info('Analyzing archive {} ({}/{})'.format(info.name, num_archives - i, num_archives))
+                archive_id = info.id
                 if archive_id not in self.chunks:
                     logger.error('Archive metadata block is missing!')
                     self.error_found = True
-                    del self.manifest.archives[name]
+                    del self.manifest.archives[info.name]
                     continue
                 mark_as_possibly_superseded(archive_id)
                 cdata = self.repository.get(archive_id)
                 _, data = self.key.decrypt(archive_id, cdata)
-                archive = StableDict(msgpack.unpackb(data))
-                if archive[b'version'] != 1:
+                archive = ArchiveItem(internal_dict=msgpack.unpackb(data))
+                if archive.version != 1:
                     raise Exception('Unknown archive metadata version')
-                decode_dict(archive, ARCHIVE_TEXT_KEYS)
-                archive[b'cmdline'] = [safe_decode(arg) for arg in archive[b'cmdline']]
+                archive.cmdline = [safe_decode(arg) for arg in archive.cmdline]
                 items_buffer = ChunkBuffer(self.key)
                 items_buffer.write_chunk = add_callback
                 for item in robust_iterator(archive):
@@ -1253,14 +1255,14 @@ class ArchiveChecker:
                         verify_file_chunks(item)
                     items_buffer.add(item)
                 items_buffer.flush(flush=True)
-                for previous_item_id in archive[b'items']:
+                for previous_item_id in archive.items:
                     mark_as_possibly_superseded(previous_item_id)
-                archive[b'items'] = items_buffer.chunks
-                data = msgpack.packb(archive, unicode_errors='surrogateescape')
+                archive.items = items_buffer.chunks
+                data = msgpack.packb(archive.as_dict(), unicode_errors='surrogateescape')
                 new_archive_id = self.key.id_hash(data)
                 cdata = self.key.encrypt(Chunk(data))
                 add_reference(new_archive_id, len(data), len(cdata), cdata)
-                info[b'id'] = new_archive_id
+                self.manifest.archives[info.name] = (new_archive_id, info.ts)
 
     def orphan_chunks_check(self):
         if self.check_all:
@@ -1483,9 +1485,9 @@ class ArchiveRecreater:
         if completed:
             timestamp = archive.ts.replace(tzinfo=None)
             if comment is None:
-                comment = archive.metadata.get(b'comment', '')
+                comment = archive.metadata.get('comment', '')
             target.save(timestamp=timestamp, comment=comment, additional_metadata={
-                'cmdline': archive.metadata[b'cmdline'],
+                'cmdline': archive.metadata.cmdline,
                 'recreate_cmdline': sys.argv,
             })
             if replace_original:
@@ -1554,7 +1556,7 @@ class ArchiveRecreater:
         if not target:
             target = self.create_target_archive(target_name)
         # If the archives use the same chunker params, then don't rechunkify
-        target.recreate_rechunkify = tuple(archive.metadata.get(b'chunker_params')) != self.chunker_params
+        target.recreate_rechunkify = tuple(archive.metadata.get('chunker_params')) != self.chunker_params
         return target, resume_from
 
     def try_resume(self, archive, target_name):
@@ -1573,7 +1575,7 @@ class ArchiveRecreater:
         return target, resume_from
 
     def incref_partial_chunks(self, source_archive, target_archive):
-        target_archive.recreate_partial_chunks = source_archive.metadata.get(b'recreate_partial_chunks', [])
+        target_archive.recreate_partial_chunks = source_archive.metadata.get('recreate_partial_chunks', [])
         for chunk_id, size, csize in target_archive.recreate_partial_chunks:
             if not self.cache.seen_chunk(chunk_id):
                 try:
@@ -1606,8 +1608,8 @@ class ArchiveRecreater:
         return item
 
     def can_resume(self, archive, old_target, target_name):
-        resume_id = old_target.metadata[b'recreate_source_id']
-        resume_args = [safe_decode(arg) for arg in old_target.metadata[b'recreate_args']]
+        resume_id = old_target.metadata.recreate_source_id
+        resume_args = [safe_decode(arg) for arg in old_target.metadata.recreate_args]
         if resume_id != archive.id:
             logger.warning('Source archive changed, will discard %s and start over', target_name)
             logger.warning('Saved fingerprint:   %s', bin_to_hex(resume_id))
diff --git a/src/borg/archiver.py b/src/borg/archiver.py
index 98a02df68..78fdfe7a3 100644
--- a/src/borg/archiver.py
+++ b/src/borg/archiver.py
@@ -679,8 +679,8 @@ class Archiver:
         archive2 = Archive(repository, key, manifest, args.archive2,
                            consider_part_files=args.consider_part_files)
 
-        can_compare_chunk_ids = archive1.metadata.get(b'chunker_params', False) == archive2.metadata.get(
-            b'chunker_params', True) or args.same_chunker_params
+        can_compare_chunk_ids = archive1.metadata.get('chunker_params', False) == archive2.metadata.get(
+            'chunker_params', True) or args.same_chunker_params
         if not can_compare_chunk_ids:
             self.print_warning('--chunker-params might be different between archives, diff will be slow.\n'
                                'If you know for certain that they are the same, pass --same-chunker-params '
@@ -734,7 +734,7 @@ class Archiver:
                     msg.append("This repository seems to have no manifest, so we can't tell anything about its contents.")
                 else:
                     msg.append("You requested to completely DELETE the repository *including* all archives it contains:")
-                    for archive_info in manifest.list_archive_infos(sort_by='ts'):
+                    for archive_info in manifest.archives.list(sort_by='ts'):
                         msg.append(format_archive(archive_info))
                 msg.append("Type 'YES' if you understand this and want to continue: ")
                 msg = '\n'.join(msg)
@@ -812,7 +812,7 @@ class Archiver:
                 format = "{archive:<36} {time} [{id}]{NL}"
             formatter = ArchiveFormatter(format)
 
-            for archive_info in manifest.list_archive_infos(sort_by='ts'):
+            for archive_info in manifest.archives.list(sort_by='ts'):
                 if args.prefix and not archive_info.name.startswith(args.prefix):
                     continue
                 write(safe_encode(formatter.format_item(archive_info)))
@@ -831,14 +831,14 @@ class Archiver:
             stats = archive.calc_stats(cache)
             print('Archive name: %s' % archive.name)
             print('Archive fingerprint: %s' % archive.fpr)
-            print('Comment: %s' % archive.metadata.get(b'comment', ''))
-            print('Hostname: %s' % archive.metadata[b'hostname'])
-            print('Username: %s' % archive.metadata[b'username'])
+            print('Comment: %s' % archive.metadata.get('comment', ''))
+            print('Hostname: %s' % archive.metadata.hostname)
+            print('Username: %s' % archive.metadata.username)
             print('Time (start): %s' % format_time(to_localtime(archive.ts)))
             print('Time (end):   %s' % format_time(to_localtime(archive.ts_end)))
             print('Duration: %s' % archive.duration_from_meta)
             print('Number of files: %d' % stats.nfiles)
-            print('Command line: %s' % format_cmdline(archive.metadata[b'cmdline']))
+            print('Command line: %s' % format_cmdline(archive.metadata.cmdline))
             print(DASHES)
             print(STATS_HEADER)
             print(str(stats))
@@ -857,7 +857,7 @@ class Archiver:
                              '"keep-secondly", "keep-minutely", "keep-hourly", "keep-daily", '
                              '"keep-weekly", "keep-monthly" or "keep-yearly" settings must be specified.')
             return self.exit_code
-        archives_checkpoints = manifest.list_archive_infos(sort_by='ts', reverse=True)  # just a ArchiveInfo list
+        archives_checkpoints = manifest.archives.list(sort_by='ts', reverse=True)  # just a ArchiveInfo list
         if args.prefix:
             archives_checkpoints = [arch for arch in archives_checkpoints if arch.name.startswith(args.prefix)]
         is_checkpoint = re.compile(r'\.checkpoint(\.\d+)?$').search
@@ -974,7 +974,7 @@ class Archiver:
                 if args.target is not None:
                     self.print_error('--target: Need to specify single archive')
                     return self.exit_code
-                for archive in manifest.list_archive_infos(sort_by='ts'):
+                for archive in manifest.archives.list(sort_by='ts'):
                     name = archive.name
                     if recreater.is_temporary_archive(name):
                         continue
@@ -1009,7 +1009,7 @@ class Archiver:
         """dump (decrypted, decompressed) archive items metadata (not: data)"""
         archive = Archive(repository, key, manifest, args.location.archive,
                           consider_part_files=args.consider_part_files)
-        for i, item_id in enumerate(archive.metadata[b'items']):
+        for i, item_id in enumerate(archive.metadata.items):
             _, data = key.decrypt(item_id, repository.get(item_id))
             filename = '%06d_%s.items' % (i, bin_to_hex(item_id))
             print('Dumping', filename)
diff --git a/src/borg/cache.py b/src/borg/cache.py
index df4b90861..f325ff25d 100644
--- a/src/borg/cache.py
+++ b/src/borg/cache.py
@@ -16,7 +16,7 @@ from .helpers import get_cache_dir
 from .helpers import decode_dict, int_to_bigint, bigint_to_int, bin_to_hex
 from .helpers import format_file_size
 from .helpers import yes
-from .item import Item
+from .item import Item, ArchiveItem
 from .key import PlaintextKey
 from .locking import Lock
 from .platform import SaveFile
@@ -279,7 +279,7 @@ Chunk index:    {0.total_unique_chunks:20d} {0.total_chunks:20d}"""
                 return set()
 
         def repo_archives():
-            return set(info[b'id'] for info in self.manifest.archives.values())
+            return set(info.id for info in self.manifest.archives.list())
 
         def cleanup_outdated(ids):
             for id in ids:
@@ -290,12 +290,11 @@ Chunk index:    {0.total_unique_chunks:20d} {0.total_chunks:20d}"""
             cdata = repository.get(archive_id)
             _, data = key.decrypt(archive_id, cdata)
             chunk_idx.add(archive_id, 1, len(data), len(cdata))
-            archive = msgpack.unpackb(data)
-            if archive[b'version'] != 1:
+            archive = ArchiveItem(internal_dict=msgpack.unpackb(data))
+            if archive.version != 1:
                 raise Exception('Unknown archive metadata version')
-            decode_dict(archive, (b'name',))
             unpacker = msgpack.Unpacker()
-            for item_id, chunk in zip(archive[b'items'], repository.get_many(archive[b'items'])):
+            for item_id, chunk in zip(archive.items, repository.get_many(archive.items)):
                 _, data = key.decrypt(item_id, chunk)
                 chunk_idx.add(item_id, 1, len(data), len(chunk))
                 unpacker.feed(data)
@@ -319,9 +318,9 @@ Chunk index:    {0.total_unique_chunks:20d} {0.total_chunks:20d}"""
             return chunk_idx
 
         def lookup_name(archive_id):
-            for name, info in self.manifest.archives.items():
-                if info[b'id'] == archive_id:
-                    return name
+            for info in self.manifest.archives.list():
+                if info.id == archive_id:
+                    return info.name
 
         def create_master_idx(chunk_idx):
             logger.info('Synchronizing chunks cache...')
diff --git a/src/borg/constants.py b/src/borg/constants.py
index d83c41f20..d6f26d116 100644
--- a/src/borg/constants.py
+++ b/src/borg/constants.py
@@ -15,8 +15,6 @@ ARCHIVE_KEYS = frozenset(['version', 'name', 'items', 'cmdline', 'hostname', 'us
 # this is the set of keys that are always present in archives:
 REQUIRED_ARCHIVE_KEYS = frozenset(['version', 'name', 'items', 'cmdline', 'time', ])
 
-ARCHIVE_TEXT_KEYS = (b'name', b'comment', b'hostname', b'username', b'time', b'time_end')
-
 # default umask, overriden by --umask, defaults to read/write only for owner
 UMASK_DEFAULT = 0o077
 
diff --git a/src/borg/fuse.py b/src/borg/fuse.py
index 3113515fe..4e7cf10c5 100644
--- a/src/borg/fuse.py
+++ b/src/borg/fuse.py
@@ -73,11 +73,11 @@ class FuseOperations(llfuse.Operations):
         if archive:
             self.process_archive(archive)
         else:
-            for archive_name in manifest.archives:
+            for name in manifest.archives:
                 # Create archive placeholder inode
                 archive_inode = self._create_dir(parent=1)
-                self.contents[1][os.fsencode(archive_name)] = archive_inode
-                self.pending_archives[archive_inode] = Archive(repository, key, manifest, archive_name)
+                self.contents[1][os.fsencode(name)] = archive_inode
+                self.pending_archives[archive_inode] = Archive(repository, key, manifest, name)
 
     def mount(self, mountpoint, mount_options, foreground=False):
         """Mount filesystem on *mountpoint* with *mount_options*."""
@@ -117,7 +117,7 @@ class FuseOperations(llfuse.Operations):
         """Build fuse inode hierarchy from archive metadata
         """
         unpacker = msgpack.Unpacker()
-        for key, chunk in zip(archive.metadata[b'items'], self.repository.get_many(archive.metadata[b'items'])):
+        for key, chunk in zip(archive.metadata.items, self.repository.get_many(archive.metadata.items)):
             _, data = self.key.decrypt(key, chunk)
             unpacker.feed(data)
             for item in unpacker:
diff --git a/src/borg/helpers.py b/src/borg/helpers.py
index f4c553836..759291442 100644
--- a/src/borg/helpers.py
+++ b/src/borg/helpers.py
@@ -18,7 +18,7 @@ import time
 import unicodedata
 import uuid
 from binascii import hexlify
-from collections import namedtuple, deque
+from collections import namedtuple, deque, abc
 from contextlib import contextmanager
 from datetime import datetime, timezone, timedelta
 from fnmatch import translate
@@ -97,12 +97,76 @@ def check_extension_modules():
         raise ExtensionModuleError
 
 
+ArchiveInfo = namedtuple('ArchiveInfo', 'name id ts')
+
+
+class Archives(abc.MutableMapping):
+    """
+    Nice wrapper around the archives dict, making sure only valid types/values get in
+    and we can deal with str keys (and it internally encodes to byte keys) and eiter
+    str timestamps or datetime timestamps.
+    """
+    def __init__(self):
+        # key: encoded archive name, value: dict(b'id': bytes_id, b'time': bytes_iso_ts)
+        self._archives = {}
+
+    def __len__(self):
+        return len(self._archives)
+
+    def __iter__(self):
+        return iter(safe_decode(name) for name in self._archives)
+
+    def __getitem__(self, name):
+        assert isinstance(name, str)
+        _name = safe_encode(name)
+        values = self._archives.get(_name)
+        if values is None:
+            raise KeyError
+        ts = parse_timestamp(values[b'time'].decode('utf-8'))
+        return ArchiveInfo(name=name, id=values[b'id'], ts=ts)
+
+    def __setitem__(self, name, info):
+        assert isinstance(name, str)
+        name = safe_encode(name)
+        assert isinstance(info, tuple)
+        id, ts = info
+        assert isinstance(id, bytes)
+        if isinstance(ts, datetime):
+            ts = ts.replace(tzinfo=None).isoformat()
+        assert isinstance(ts, str)
+        ts = ts.encode()
+        self._archives[name] = {b'id': id, b'time': ts}
+
+    def __delitem__(self, name):
+        assert isinstance(name, str)
+        name = safe_encode(name)
+        del self._archives[name]
+
+    def list(self, sort_by=None, reverse=False):
+        # inexpensive Archive.list_archives replacement if we just need .name, .id, .ts
+        archives = self.values()  # [self[name] for name in self]
+        if sort_by is not None:
+            archives = sorted(archives, key=attrgetter(sort_by), reverse=reverse)
+        return archives
+
+    def set_raw_dict(self, d):
+        """set the dict we get from the msgpack unpacker"""
+        for k, v in d.items():
+            assert isinstance(k, bytes)
+            assert isinstance(v, dict) and b'id' in v and b'time' in v
+            self._archives[k] = v
+
+    def get_raw_dict(self):
+        """get the dict we can give to the msgpack packer"""
+        return self._archives
+
+
 class Manifest:
 
     MANIFEST_ID = b'\0' * 32
 
     def __init__(self, key, repository, item_keys=None):
-        self.archives = {}
+        self.archives = Archives()
         self.config = {}
         self.key = key
         self.repository = repository
@@ -114,6 +178,7 @@ class Manifest:
 
     @classmethod
     def load(cls, repository, key=None):
+        from .item import ManifestItem
         from .key import key_factory
         from .repository import Repository
         try:
@@ -125,42 +190,30 @@ class Manifest:
         manifest = cls(key, repository)
         _, data = key.decrypt(None, cdata)
         manifest.id = key.id_hash(data)
-        m = msgpack.unpackb(data)
-        if not m.get(b'version') == 1:
+        m = ManifestItem(internal_dict=msgpack.unpackb(data))
+        if m.get('version') != 1:
             raise ValueError('Invalid manifest version')
-        manifest.archives = dict((k.decode('utf-8'), v) for k, v in m[b'archives'].items())
-        manifest.timestamp = m.get(b'timestamp')
-        if manifest.timestamp:
-            manifest.timestamp = manifest.timestamp.decode('ascii')
-        manifest.config = m[b'config']
+        manifest.archives.set_raw_dict(m.archives)
+        manifest.timestamp = m.get('timestamp')
+        manifest.config = m.config
         # valid item keys are whatever is known in the repo or every key we know
-        manifest.item_keys = ITEM_KEYS | frozenset(key.decode() for key in m.get(b'item_keys', []))
+        manifest.item_keys = ITEM_KEYS | frozenset(key.decode() for key in m.get('item_keys', []))
         return manifest, key
 
     def write(self):
+        from .item import ManifestItem
         self.timestamp = datetime.utcnow().isoformat()
-        data = msgpack.packb(StableDict({
-            'version': 1,
-            'archives': self.archives,
-            'timestamp': self.timestamp,
-            'config': self.config,
-            'item_keys': tuple(self.item_keys),
-        }))
+        manifest = ManifestItem(
+            version=1,
+            archives=self.archives.get_raw_dict(),
+            timestamp=self.timestamp,
+            config=self.config,
+            item_keys=tuple(self.item_keys),
+        )
+        data = msgpack.packb(manifest.as_dict())
         self.id = self.key.id_hash(data)
         self.repository.put(self.MANIFEST_ID, self.key.encrypt(Chunk(data)))
 
-    def list_archive_infos(self, sort_by=None, reverse=False):
-        # inexpensive Archive.list_archives replacement if we just need .name, .id, .ts
-        ArchiveInfo = namedtuple('ArchiveInfo', 'name id ts')
-        archives = []
-        for name, values in self.archives.items():
-            ts = parse_timestamp(values[b'time'].decode('utf-8'))
-            id = values[b'id']
-            archives.append(ArchiveInfo(name=name, id=id, ts=ts))
-        if sort_by is not None:
-            archives = sorted(archives, key=attrgetter(sort_by), reverse=reverse)
-        return archives
-
 
 def prune_within(archives, within):
     multiplier = {'H': 1, 'd': 24, 'w': 24 * 7, 'm': 24 * 31, 'y': 24 * 365}
diff --git a/src/borg/item.py b/src/borg/item.py
index 90289dbe8..0a0908c02 100644
--- a/src/borg/item.py
+++ b/src/borg/item.py
@@ -204,3 +204,61 @@ class Key(PropDict):
     enc_hmac_key = PropDict._make_property('enc_hmac_key', bytes)
     id_key = PropDict._make_property('id_key', bytes)
     chunk_seed = PropDict._make_property('chunk_seed', int)
+
+
+class ArchiveItem(PropDict):
+    """
+    ArchiveItem abstraction that deals with validation and the low-level details internally:
+
+    An ArchiveItem is created either from msgpack unpacker output, from another dict, from kwargs or
+    built step-by-step by setting attributes.
+
+    msgpack gives us a dict with bytes-typed keys, just give it to ArchiveItem(d) and use arch.xxx later.
+
+    If a ArchiveItem shall be serialized, give as_dict() method output to msgpack packer.
+    """
+
+    VALID_KEYS = {'version', 'name', 'items', 'cmdline', 'hostname', 'username', 'time', 'time_end',
+                  'comment', 'chunker_params',
+                  'recreate_cmdline', 'recreate_source_id', 'recreate_args', 'recreate_partial_chunks',
+                  }  # str-typed keys
+
+    __slots__ = ("_dict", )  # avoid setting attributes not supported by properties
+
+    version = PropDict._make_property('version', int)
+    name = PropDict._make_property('name', str, 'surrogate-escaped str', encode=safe_encode, decode=safe_decode)
+    items = PropDict._make_property('items', list)
+    cmdline = PropDict._make_property('cmdline', list)  # list of s-e-str
+    hostname = PropDict._make_property('hostname', str, 'surrogate-escaped str', encode=safe_encode, decode=safe_decode)
+    username = PropDict._make_property('username', str, 'surrogate-escaped str', encode=safe_encode, decode=safe_decode)
+    time = PropDict._make_property('time', str, 'surrogate-escaped str', encode=safe_encode, decode=safe_decode)
+    time_end = PropDict._make_property('time_end', str, 'surrogate-escaped str', encode=safe_encode, decode=safe_decode)
+    comment = PropDict._make_property('comment', str, 'surrogate-escaped str', encode=safe_encode, decode=safe_decode)
+    chunker_params = PropDict._make_property('chunker_params', tuple)
+    recreate_source_id = PropDict._make_property('recreate_source_id', bytes)
+    recreate_cmdline = PropDict._make_property('recreate_cmdline', list)  # list of s-e-str
+    recreate_args = PropDict._make_property('recreate_args', list)  # list of s-e-str
+    recreate_partial_chunks = PropDict._make_property('recreate_partial_chunks', list)  # list of tuples
+
+
+class ManifestItem(PropDict):
+    """
+    ManifestItem abstraction that deals with validation and the low-level details internally:
+
+    A ManifestItem is created either from msgpack unpacker output, from another dict, from kwargs or
+    built step-by-step by setting attributes.
+
+    msgpack gives us a dict with bytes-typed keys, just give it to ManifestItem(d) and use manifest.xxx later.
+
+    If a ManifestItem shall be serialized, give as_dict() method output to msgpack packer.
+    """
+
+    VALID_KEYS = {'version', 'archives', 'timestamp', 'config', 'item_keys', }  # str-typed keys
+
+    __slots__ = ("_dict", )  # avoid setting attributes not supported by properties
+
+    version = PropDict._make_property('version', int)
+    archives = PropDict._make_property('archives', dict)  # name -> dict
+    timestamp = PropDict._make_property('time', str, 'surrogate-escaped str', encode=safe_encode, decode=safe_decode)
+    config = PropDict._make_property('config', dict)
+    item_keys = PropDict._make_property('item_keys', tuple)
diff --git a/src/borg/remote.py b/src/borg/remote.py
index ff057b7b0..18637cae7 100644
--- a/src/borg/remote.py
+++ b/src/borg/remote.py
@@ -283,22 +283,23 @@ This problem will go away as soon as the server has been upgraded to 1.0.7+.
             return msgid
 
         def handle_error(error, res):
-            if error == b'DoesNotExist':
+            error = error.decode('utf-8')
+            if error == 'DoesNotExist':
                 raise Repository.DoesNotExist(self.location.orig)
-            elif error == b'AlreadyExists':
+            elif error == 'AlreadyExists':
                 raise Repository.AlreadyExists(self.location.orig)
-            elif error == b'CheckNeeded':
+            elif error == 'CheckNeeded':
                 raise Repository.CheckNeeded(self.location.orig)
-            elif error == b'IntegrityError':
+            elif error == 'IntegrityError':
                 raise IntegrityError(res)
-            elif error == b'PathNotAllowed':
+            elif error == 'PathNotAllowed':
                 raise PathNotAllowed(*res)
-            elif error == b'ObjectNotFound':
+            elif error == 'ObjectNotFound':
                 raise Repository.ObjectNotFound(res[0], self.location.orig)
-            elif error == b'InvalidRPCMethod':
+            elif error == 'InvalidRPCMethod':
                 raise InvalidRPCMethod(*res)
             else:
-                raise self.RPCError(res.decode('utf-8'), error.decode('utf-8'))
+                raise self.RPCError(res.decode('utf-8'), error)
 
         calls = list(calls)
         waiting_for = []
diff --git a/src/borg/testsuite/archive.py b/src/borg/testsuite/archive.py
index 19db1a44c..49648ef47 100644
--- a/src/borg/testsuite/archive.py
+++ b/src/borg/testsuite/archive.py
@@ -8,7 +8,7 @@ import msgpack
 
 from ..archive import Archive, CacheChunkBuffer, RobustUnpacker, valid_msgpacked_dict, ITEM_KEYS, Statistics
 from ..archive import BackupOSError, backup_io, backup_io_iter
-from ..item import Item
+from ..item import Item, ArchiveItem
 from ..key import PlaintextKey
 from ..helpers import Manifest
 from . import BaseTestCase
@@ -77,7 +77,7 @@ class ArchiveTimestampTestCase(BaseTestCase):
         key = PlaintextKey(repository)
         manifest = Manifest(repository, key)
         a = Archive(repository, key, manifest, 'test', create=True)
-        a.metadata = {b'time': isoformat}
+        a.metadata = ArchiveItem(time=isoformat)
         self.assert_equal(a.ts, expected)
 
     def test_with_microseconds(self):
diff --git a/src/borg/testsuite/archiver.py b/src/borg/testsuite/archiver.py
index 2df01b29e..1901b8d49 100644
--- a/src/borg/testsuite/archiver.py
+++ b/src/borg/testsuite/archiver.py
@@ -1859,7 +1859,7 @@ class ArchiverCheckTestCase(ArchiverTestCaseBase):
     def test_missing_archive_item_chunk(self):
         archive, repository = self.open_archive('archive1')
         with repository:
-            repository.delete(archive.metadata[b'items'][-5])
+            repository.delete(archive.metadata.items[-5])
             repository.commit()
         self.cmd('check', self.repository_location, exit_code=1)
         self.cmd('check', '--repair', self.repository_location, exit_code=0)
diff --git a/src/borg/testsuite/key.py b/src/borg/testsuite/key.py
index 856970107..b85650a4f 100644
--- a/src/borg/testsuite/key.py
+++ b/src/borg/testsuite/key.py
@@ -69,9 +69,9 @@ class TestKey:
         monkeypatch.setenv('BORG_PASSPHRASE', 'test')
         key = KeyfileKey.create(self.MockRepository(), self.MockArgs())
         assert bytes_to_long(key.enc_cipher.iv, 8) == 0
-        manifest = key.encrypt(Chunk(b'XXX'))
+        manifest = key.encrypt(Chunk(b'ABC'))
         assert key.extract_nonce(manifest) == 0
-        manifest2 = key.encrypt(Chunk(b'XXX'))
+        manifest2 = key.encrypt(Chunk(b'ABC'))
         assert manifest != manifest2
         assert key.decrypt(None, manifest) == key.decrypt(None, manifest2)
         assert key.extract_nonce(manifest2) == 1
@@ -91,7 +91,7 @@ class TestKey:
         assert not keyfile.exists()
         key = KeyfileKey.create(self.MockRepository(), self.MockArgs())
         assert keyfile.exists()
-        chunk = Chunk(b'XXX')
+        chunk = Chunk(b'ABC')
         chunk_id = key.id_hash(chunk.data)
         chunk_cdata = key.encrypt(chunk)
         key = KeyfileKey.detect(self.MockRepository(), chunk_cdata)
@@ -124,9 +124,9 @@ class TestKey:
         assert hexlify(key.enc_hmac_key) == b'b885a05d329a086627412a6142aaeb9f6c54ab7950f996dd65587251f6bc0901'
         assert hexlify(key.enc_key) == b'2ff3654c6daf7381dbbe718d2b20b4f1ea1e34caa6cc65f6bb3ac376b93fed2a'
         assert key.chunk_seed == -775740477
-        manifest = key.encrypt(Chunk(b'XXX'))
+        manifest = key.encrypt(Chunk(b'ABC'))
         assert key.extract_nonce(manifest) == 0
-        manifest2 = key.encrypt(Chunk(b'XXX'))
+        manifest2 = key.encrypt(Chunk(b'ABC'))
         assert manifest != manifest2
         assert key.decrypt(None, manifest) == key.decrypt(None, manifest2)
         assert key.extract_nonce(manifest2) == 1