diff --git a/app/internal/sync.py b/app/internal/sync.py
index 931044f4..39d8474c 100755
--- a/app/internal/sync.py
+++ b/app/internal/sync.py
@@ -8,8 +8,11 @@
 
 from app.database.query import get_all_templates, get_interface
 from app.dependencies import get_database, get_preferences
-from app.internal.series import add_series
+from app.internal.cards import delete_cards
+from app.internal.series import add_series, delete_series
+from app.models.card import Card
 from app.models.connection import Connection
+from app.models.loaded import Loaded
 from app.models.series import Series
 from app.models.sync import Sync
 from app.schemas.series import NewSeries
@@ -24,27 +27,57 @@ def sync_all(*, log: Logger = log) -> None:
     Schedule-able function to run all defined Syncs in the Database.
     """
 
+    # Wait if there is a Sync currently running
+    attempts = 5
+    while ((preferences := get_preferences()).currently_running_sync is not None
+        and attempts > 0):
+        log.debug('Sync is current running, waiting..')
+        sleep(60)
+        attempts -= 1
+
     try:
-        # Get the Database
         with next(get_database()) as db:
-            # Get and run all Syncs
-            for sync in db.query(Sync).all():
+            # Exit if there are no Syncs
+            if not (syncs := db.query(Sync).all()):
+                return None
+
+            # Run each Sync
+            for sync in syncs:
                 try:
                     run_sync(db, sync, log=log)
-                except HTTPException as e:
-                    log.exception(f'{sync} Error Syncing - {e.detail}', e)
+                except HTTPException as exc:
+                    log.exception(f'{sync} Error Syncing - {exc.detail}')
                 except OperationalError:
-                    log.debug(f'Database is busy, sleeping..')
+                    log.debug('Database is busy, sleeping..')
                     sleep(30)
+
+            # Remove un-synced Series if toggled
+            if preferences.delete_unsynced_series:
+                # Delete all Series which do not have an associated Sync
+                to_delete = db.query(Series)\
+                    .filter(Series.sync_id.is_(None))\
+                    .all()
+                for series in to_delete:
+                    # Delete Cards and Loaded objects
+                    delete_cards(
+                        db,
+                        db.query(Card).filter_by(series_id=series.id),
+                        db.query(Loaded).filter_by(series_id=series.id),
+                        commit=False,
+                        log=log,
+                    )
+                    # Delete Series itself
+                    delete_series(db, series, commit_changes=False, log=log)
                 db.commit()
-    except Exception as e:
-        log.exception(f'Failed to run all Syncs', e)
-    get_preferences().currently_running_sync = None
+    except Exception:
+        log.exception('Failed to run all Syncs')
+
+    preferences.currently_running_sync = None
 
 
 def add_sync(
         db: Session,
-        new_sync: Union[NewEmbySync, NewJellyfinSync, NewPlexSync,NewSonarrSync],
+        new_sync: Union[NewEmbySync, NewJellyfinSync,NewPlexSync,NewSonarrSync],
         *,
         log: Logger = log,
     ) -> Sync:
@@ -118,6 +151,7 @@ def run_sync(
 
     # Process all Series returned by Sync
     added: list[Series] = []
+    existing_series: set[Series] = set()
     for series_info, lib_or_dir in all_series:
         # Look for existing Series
         existing = db.query(Series)\
@@ -153,6 +187,10 @@ def run_sync(
 
         # If already exists in Database, update IDs and libraries then skip
         if existing:
+            existing_series.add(existing)
+            # Assign Sync ID if one does not already exist
+            existing.sync_id = existing.sync_id or sync.id
+
             # Add any new libraries
             for new in libraries:
                 exists = any(
@@ -167,17 +205,25 @@ def run_sync(
             # Update IDs
             existing.update_from_series_info(series_info)
             db.commit()
-            continue
-
         # Create NewSeries for this entry
-        added.append(NewSeries(
-            name=series_info.name, year=series_info.year, libraries=libraries,
-            **series_info.ids, sync_id=sync.id, template_ids=sync.template_ids,
-        ))
+        else:
+            added.append(NewSeries(
+                name=series_info.name, year=series_info.year,
+                libraries=libraries, **series_info.ids,
+                sync_id=sync.id, template_ids=sync.template_ids,
+            ))
 
     # Nothing added, log
     if not added:
-        log.debug(f'{sync} No new Series synced')
+        log.info(f'{sync} No new Series synced')
+
+    # Clear the Sync ID of all Series which were not in the latest sync
+    if preferences.delete_unsynced_series:
+        for series in sync.series:
+            if series not in existing_series:
+                series.sync_id = None
+                log.debug(f'Series[{series.id}].sync_id = None')
+        db.commit()
 
     # Process each newly added Series
     preferences.currently_running_sync = None
diff --git a/app/models/preferences.py b/app/models/preferences.py
index 7f0d777f..5464b074 100755
--- a/app/models/preferences.py
+++ b/app/models/preferences.py
@@ -76,6 +76,7 @@ class Preferences:
         'imported_blueprints', 'colorblind_mode', 'library_unique_cards',
         'invalid_connections', 'home_page_table_view', 'reduced_animations',
         'currently_running_sync', 'interactive_card_previews',
+        'home_page_order', 'delete_unsynced_series',
     )
 
 
@@ -186,6 +187,7 @@ def __initialize_defaults(self) -> None:
         self.completely_delete_series = False
         self.sync_specials = True
         self.delete_missing_episodes = True
+        self.delete_unsynced_series = False
         self.simplified_data_table = True
         self.interactive_card_previews = True
         self.remote_card_types = {}
@@ -197,7 +199,7 @@ def __initialize_defaults(self) -> None:
         self.default_templates: list[int] = []
         self.global_extras: dict[str, dict[str, str]] = {}
 
-        self.currently_running_sync = None
+        self.currently_running_sync: Optional[int] = None
         self.invalid_connections: list[int] = []
         self.use_emby = False
         self.use_jellyfin = False
diff --git a/app/schemas/preferences.py b/app/schemas/preferences.py
index 26422563..cbc9151a 100755
--- a/app/schemas/preferences.py
+++ b/app/schemas/preferences.py
@@ -3,7 +3,7 @@
 from pathlib import Path
 from typing import Literal, Optional
 
-from pydantic import DirectoryPath, PositiveInt, conint, constr, validator # pylint: disable=no-name-in-module
+from pydantic import DirectoryPath, PositiveInt, conint, constr, validator
 
 from app.schemas.base import (
     Base, InterfaceType, ImageSource, UpdateBase, UNSPECIFIED
@@ -79,6 +79,7 @@ class UpdatePreferences(UpdateBase):
     season_folder_format: str = UNSPECIFIED
     sync_specials: bool = UNSPECIFIED
     delete_missing_episodes: bool = UNSPECIFIED
+    delete_unsynced_series: bool = UNSPECIFIED
     simplified_data_table: bool = UNSPECIFIED
     default_card_type: CardTypeIdentifier = UNSPECIFIED
     excluded_card_types: list[CardTypeIdentifier] = UNSPECIFIED
@@ -157,6 +158,7 @@ class Preferences(Base):
     season_folder_format: str
     sync_specials: bool
     delete_missing_episodes: bool
+    delete_unsynced_series: bool
     simplified_data_table: bool
     is_docker: bool
     default_card_type: CardTypeIdentifier
diff --git a/app/templates/js/settings.js b/app/templates/js/settings.js
index 0a9242eb..329b0ce9 100755
--- a/app/templates/js/settings.js
+++ b/app/templates/js/settings.js
@@ -171,11 +171,12 @@ function updateGlobalSettings() {
     card_directory: $('input[name="card_directory"]').val(),
     source_directory: $('input[name="source_directory"]').val(),
     completely_delete_series: $('input[name="completely_delete_series"]').is(':checked'),
-    // Episode Data
+    // Series and Episode Data
     episode_data_source: $('input[name="episode_data_source"]').val(),
     image_source_priority: $('input[name="image_source_priority"]').val().split(','),
     sync_specials: $('input[name="sync_specials"]').is(':checked'),
     delete_missing_episodes: $('input[name="delete_missing_episodes"]').is(':checked'),
+    delete_unsynced_series: $('input[name="delete_unsynced_series"]').is(':checked'),
     // Title Cards
     default_card_type: $('input[name="default_card_type"]').val(),
     excluded_card_types: parseListString($('input[name="excluded_card_types"]').val()),
diff --git a/app/templates/settings.html b/app/templates/settings.html
index c9fe8438..8c8ab06f 100755
--- a/app/templates/settings.html
+++ b/app/templates/settings.html
@@ -84,8 +84,8 @@ <h3 class="ui horizontal divider header">
 
             <!-- Episode Data Settings -->
             <h3 class="ui horizontal divider header">
-              <i class="layer group icon"></i>
-              Episode Data
+              <i class="database icon"></i>
+              Series and Episode Data
             </h3>
             <section>
               <div class="two fields">
@@ -143,6 +143,22 @@ <h3 class="ui horizontal divider header">
                   <p class="help">Whether to delete Episodes no longer present in the assigned Episode Data Source.</p>
                 </div>
               </div>
+
+              <div class="two fields">
+                <div class="ui checkbox field">
+                  <label>Delete Un-Synced Series</label>
+                  {% if preferences.delete_unsynced_series %}
+                  <input name="delete_unsynced_series" type="checkbox" checked="checked">
+                  {% else %}
+                  <input name="delete_unsynced_series" type="checkbox">
+                  {% endif %}
+                  <p class="help">
+                    Whether to delete Series which no longer appear in any Syncs.
+                    <br>
+                    <b>This will delete all Title Cards and manually added Series (if they are not in any Sync).</b>
+                  </p>
+                </div>
+              </div>
             </section>
 
             <!-- Title Card Settings -->
@@ -189,7 +205,7 @@ <h3 class="ui horizontal divider header">
                   <label>Watched Episode Style</label>
                   <div class="ui long compact selection dropdown">
                     <span class="default text">{{preferences.default_watched_style.title()}}</span>
-                    <input name="default_watched_style" type="hidden">
+                    <input name="default_watched_style" type="hidden" value="{{preferences.default_watched_style}}">
                     <i class="dropdown icon"></i>
                     <div class="menu">
                       <div class="header">Art Variations</div>
@@ -198,6 +214,7 @@ <h3 class="ui horizontal divider header">
                       <div class="item" data-value="art blur">Blurred Art</div>
                       <div class="item" data-value="art grayscale">Grayscale Art</div>
                       <div class="item" data-value="art blur grayscale">Blurred Grayscale Art</div>
+
                       <div class="header">Unique Variations</div>
                       <div class="divider"></div>
                       <div class="item" data-value="unique">Unique</div>
@@ -220,7 +237,7 @@ <h3 class="ui horizontal divider header">
                   <label>Unwatched Episode Style</label>
                   <div class="ui long compact selection dropdown">
                     <span class="default text">{{preferences.default_unwatched_style.title()}}</span>
-                    <input name="default_unwatched_style" type="hidden">
+                    <input name="default_unwatched_style" type="hidden" value="{{preferences.default_unwatched_style}}">
                     <i class="dropdown icon"></i>
                     <div class="menu">
                       <div class="header">Art</div>
diff --git a/modules/ref/version_webui b/modules/ref/version_webui
index 3bd1a5fa..1cf24c17 100755
--- a/modules/ref/version_webui
+++ b/modules/ref/version_webui
@@ -1 +1 @@
-v2.0-alpha.10.1-webui68
\ No newline at end of file
+v2.0-alpha.10.1-webui69
\ No newline at end of file