diff --git a/src/GameLogic/CastleSiege/CastleSiegeConfiguration.cs b/src/GameLogic/CastleSiege/CastleSiegeConfiguration.cs
index d969d8d..6e18241 100644
--- a/src/GameLogic/CastleSiege/CastleSiegeConfiguration.cs
+++ b/src/GameLogic/CastleSiege/CastleSiegeConfiguration.cs
@@ -31,6 +31,23 @@ public class CastleSiegeConfiguration
     /// </summary>
     public int RegistrationFee { get; set; } = 100000;
 
+    // --- Persisted runtime state (P4 persistence) ---
+    // These ride on the plugin's custom-configuration JSON (already stored in PostgreSQL), so the castle
+    // owner and the current cycle survive server restarts without a dedicated database table/migration.
+    // Written by CastleSiegeEventPlugIn whenever the state changes; read back on startup to restore it.
+
+    /// <summary>Gets or sets the persisted castle owner guild name (null = unowned).</summary>
+    public string? PersistedOwnerGuildName { get; set; }
+
+    /// <summary>Gets or sets the persisted current phase, so the cycle resumes after a restart.</summary>
+    public CastleSiegePhase PersistedPhase { get; set; } = CastleSiegePhase.Ownership;
+
+    /// <summary>Gets or sets when the persisted phase started (UTC), or null if never persisted.</summary>
+    public DateTime? PersistedPhaseStartedUtc { get; set; }
+
+    /// <summary>Gets or sets the persisted registered guild names for the current cycle.</summary>
+    public IList<string> PersistedRegisteredGuilds { get; set; } = new List<string>();
+
     /// <summary>
     /// Returns true if <paramref name="now"/> falls within a 5-second window of any configured
     /// registration-open time.
diff --git a/src/GameLogic/CastleSiege/CastleSiegeContext.cs b/src/GameLogic/CastleSiege/CastleSiegeContext.cs
index 23e776e..f23ff94 100644
--- a/src/GameLogic/CastleSiege/CastleSiegeContext.cs
+++ b/src/GameLogic/CastleSiege/CastleSiegeContext.cs
@@ -22,6 +22,7 @@ public class CastleSiegeContext
     private DateTime _phaseStartedUtc;
     private string? _occupier;
     private int _defensesRemaining;
+    private bool _dirty;
 
     /// <summary>Initializes a new instance of the <see cref="CastleSiegeContext"/> class.</summary>
     /// <param name="configuration">The cycle timing configuration.</param>
@@ -40,6 +41,9 @@ public class CastleSiegeContext
     /// <summary>Gets the current phase.</summary>
     public CastleSiegePhase Phase { get; private set; }
 
+    /// <summary>Gets the UTC time the current phase started (used for persistence/restore).</summary>
+    public DateTime PhaseStartedUtc => this._phaseStartedUtc;
+
     /// <summary>Gets the current owner guild name, or null if unowned.</summary>
     public string? OwnerGuildName { get; private set; }
 
@@ -134,12 +138,50 @@ public class CastleSiegeContext
             && !this._registeredGuilds.Contains(guildName))
         {
             this._registeredGuilds.Add(guildName);
+            this._dirty = true;
         }
     }
 
     /// <summary>Admin: sets (or clears) the current owner guild name.</summary>
     /// <param name="guildName">The owner guild name, or null to clear.</param>
-    public void SetOwner(string? guildName) => this.OwnerGuildName = guildName;
+    public void SetOwner(string? guildName)
+    {
+        this.OwnerGuildName = guildName;
+        this._dirty = true;
+    }
+
+    /// <summary>
+    /// Returns whether the persistable state changed since the last call, resetting the flag.
+    /// Called each tick by the plugin to decide whether to write state to the database.
+    /// </summary>
+    public bool ConsumeDirty()
+    {
+        var dirty = this._dirty;
+        this._dirty = false;
+        return dirty;
+    }
+
+    /// <summary>
+    /// Restores persisted state on startup (owner, phase, phase-start, registrations) directly, without
+    /// firing <see cref="PhaseChanged"/> or marking the state dirty. Battle state stays cleared.
+    /// </summary>
+    /// <param name="owner">The persisted owner guild name, or null.</param>
+    /// <param name="phase">The persisted phase.</param>
+    /// <param name="phaseStartedUtc">When the persisted phase started (UTC), or null to keep the default.</param>
+    /// <param name="registeredGuilds">The persisted registered guild names, or null.</param>
+    public void RestoreState(string? owner, CastleSiegePhase phase, DateTime? phaseStartedUtc, IEnumerable<string>? registeredGuilds)
+    {
+        this.OwnerGuildName = owner;
+        this.Phase = phase;
+        this._phaseStartedUtc = phaseStartedUtc ?? this._phaseStartedUtc;
+        this._registeredGuilds.Clear();
+        if (registeredGuilds is not null)
+        {
+            this._registeredGuilds.AddRange(registeredGuilds);
+        }
+
+        this._dirty = false;
+    }
 
     /// <summary>Sets how many castle defenses (gates + guardian statues) exist this siege (when spawned).</summary>
     /// <param name="count">The defense count.</param>
@@ -222,6 +264,7 @@ public class CastleSiegeContext
     {
         this.Phase = phase;
         this._phaseStartedUtc = now;
+        this._dirty = true;
         this.PhaseChanged?.Invoke(phase);
         return ValueTask.CompletedTask;
     }
diff --git a/src/GameLogic/PlugIns/PeriodicTasks/CastleSiegeEventPlugIn.cs b/src/GameLogic/PlugIns/PeriodicTasks/CastleSiegeEventPlugIn.cs
index 3571ff1..a9b72ef 100644
--- a/src/GameLogic/PlugIns/PeriodicTasks/CastleSiegeEventPlugIn.cs
+++ b/src/GameLogic/PlugIns/PeriodicTasks/CastleSiegeEventPlugIn.cs
@@ -69,7 +69,12 @@ public sealed class CastleSiegeEventPlugIn : IPeriodicTaskPlugIn, ISupportCustom
     {
         var context = Contexts.GetOrAdd(gameContext, gc =>
         {
-            var created = new CastleSiegeContext(this.Configuration ?? new CastleSiegeConfiguration());
+            var config = this.Configuration ?? new CastleSiegeConfiguration();
+            var created = new CastleSiegeContext(config);
+
+            // Restore state persisted before the last restart (owner/phase/registrations) BEFORE subscribing,
+            // so restoring doesn't announce phases or re-spawn defenses.
+            created.RestoreState(config.PersistedOwnerGuildName, config.PersistedPhase, config.PersistedPhaseStartedUtc, config.PersistedRegisteredGuilds);
 
             // Announce phase changes to the whole server and, when the siege begins, warp registered members.
             created.PhaseChanged += phase => _ = OnPhaseChangedAsync(gc, created, phase);
@@ -84,6 +89,12 @@ public sealed class CastleSiegeEventPlugIn : IPeriodicTaskPlugIn, ISupportCustom
         {
             await ProcessSiegeTickAsync(gameContext, context).ConfigureAwait(false);
         }
+
+        // Persist owner/phase/registrations to the database whenever they changed, so they survive a restart.
+        if (context.ConsumeDirty())
+        {
+            await this.PersistStateAsync(gameContext, context).ConfigureAwait(false);
+        }
     }
 
     /// <inheritdoc />
@@ -124,6 +135,41 @@ public sealed class CastleSiegeEventPlugIn : IPeriodicTaskPlugIn, ISupportCustom
         }
     }
 
+    private async ValueTask PersistStateAsync(GameContext gameContext, CastleSiegeContext context)
+    {
+        try
+        {
+            if (this.Configuration is not { } config)
+            {
+                return;
+            }
+
+            // Snapshot the live context into the persisted config fields.
+            config.PersistedOwnerGuildName = context.OwnerGuildName;
+            config.PersistedPhase = context.Phase;
+            config.PersistedPhaseStartedUtc = context.PhaseStartedUtc;
+            config.PersistedRegisteredGuilds = context.RegisteredGuilds.ToList();
+
+            // Write the plugin's custom-configuration JSON row back to the database (durable across restarts).
+            var pluginTypeId = typeof(CastleSiegeEventPlugIn).GUID;
+            using var ctx = gameContext.PersistenceContextProvider.CreateNewContext(gameContext.Configuration);
+            var configurations = await ctx.GetAsync<PlugInConfiguration>().ConfigureAwait(false);
+            var row = configurations.FirstOrDefault(c => c.TypeId == pluginTypeId);
+            if (row is null)
+            {
+                return;
+            }
+
+            row.SetConfiguration(config, gameContext.PlugInManager.CustomConfigReferenceHandler);
+            await ctx.SaveChangesAsync().ConfigureAwait(false);
+        }
+        catch (Exception ex)
+        {
+            gameContext.LoggerFactory.CreateLogger<CastleSiegeEventPlugIn>()
+                .LogError(ex, "Castle Siege: error while persisting state to the database.");
+        }
+    }
+
     private static ValueTask AnnounceAsync(IGameContext gameContext, string message)
         => gameContext.ForEachPlayerAsync(player =>
             player.InvokeViewPlugInAsync<IShowMessagePlugIn>(p => p.ShowMessageAsync(message, MessageType.GoldenCenter)).AsTask());
diff --git a/tests/MUnique.OpenMU.Tests/CastleSiege/CastleSiegeContextTest.cs b/tests/MUnique.OpenMU.Tests/CastleSiege/CastleSiegeContextTest.cs
index bb3cd06..e5b16d1 100644
--- a/tests/MUnique.OpenMU.Tests/CastleSiege/CastleSiegeContextTest.cs
+++ b/tests/MUnique.OpenMU.Tests/CastleSiege/CastleSiegeContextTest.cs
@@ -123,6 +123,41 @@ public class CastleSiegeContextTest
         Assert.That(ctx.OccupierGuildName, Is.Null);
     }
 
+    /// <summary>Tests that restoring persisted state sets phase/owner/registrations without raising PhaseChanged.</summary>
+    [Test]
+    public void RestoreStateSetsStateWithoutFiringPhaseChanged()
+    {
+        var ctx = new CastleSiegeContext(Config());
+        var phaseChangedFired = false;
+        ctx.PhaseChanged += _ => phaseChangedFired = true;
+
+        ctx.RestoreState("Winners", CastleSiegePhase.Ownership, T0, new[] { "Winners", "Losers" });
+
+        Assert.That(ctx.Phase, Is.EqualTo(CastleSiegePhase.Ownership));
+        Assert.That(ctx.OwnerGuildName, Is.EqualTo("Winners"));
+        Assert.That(ctx.RegisteredGuilds, Is.EquivalentTo(new[] { "Winners", "Losers" }));
+        Assert.That(phaseChangedFired, Is.False);
+        Assert.That(ctx.ConsumeDirty(), Is.False, "restore must not mark the state dirty");
+    }
+
+    /// <summary>Tests that state-changing operations flip the dirty flag, which ConsumeDirty reads-and-resets.</summary>
+    [Test]
+    public async Task DirtyFlagTracksPersistableChangesAsync()
+    {
+        var ctx = new CastleSiegeContext(Config());
+        Assert.That(ctx.ConsumeDirty(), Is.False, "a fresh context has nothing to persist");
+
+        await ctx.ForceStartRegistrationAsync(T0); // phase transition -> dirty
+        Assert.That(ctx.ConsumeDirty(), Is.True);
+        Assert.That(ctx.ConsumeDirty(), Is.False, "ConsumeDirty resets the flag");
+
+        ctx.RegisterGuild("Attackers"); // registration -> dirty
+        Assert.That(ctx.ConsumeDirty(), Is.True);
+
+        ctx.SetOwner("Attackers"); // owner change -> dirty
+        Assert.That(ctx.ConsumeDirty(), Is.True);
+    }
+
     private static CastleSiegeConfiguration Config() => new()
     {
         RegistrationDuration = TimeSpan.FromMinutes(5),