diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/VirtualTags/VirtualTagHostActor.cs b/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/VirtualTags/VirtualTagHostActor.cs
index fc6f79d5..6bc2cb7c 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/VirtualTags/VirtualTagHostActor.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/VirtualTags/VirtualTagHostActor.cs
@@ -2,6 +2,8 @@ using Akka.Actor;
 using Akka.Event;
 using ZB.MOM.WW.OtOpcUa.Commons.Engines;
 using ZB.MOM.WW.OtOpcUa.Commons.OpcUa;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+using ZB.MOM.WW.OtOpcUa.Core.VirtualTags;
 using ZB.MOM.WW.OtOpcUa.OpcUaServer;
 using ZB.MOM.WW.OtOpcUa.Runtime.OpcUa;
 
@@ -33,6 +35,9 @@ public sealed class VirtualTagHostActor : ReceiveActor
     private readonly IActorRef _publishActor;
     private readonly IActorRef? _mux;
     private readonly IVirtualTagEvaluator _evaluator;
+    // Sink for historized VirtualTag results (plans with Historize=true). NullHistoryWriter when no
+    // durable historian is wired, so OnResult always has a non-null target.
+    private readonly IHistoryWriter _history;
     private readonly ILoggingAdapter _log = Context.GetLogger();
 
     // vtagId -> spawned child VirtualTagActor.
@@ -50,20 +55,27 @@ public sealed class VirtualTagHostActor : ReceiveActor
     /// <param name="mux">Optional dependency multiplexer; passed to each spawned child so it can
     /// register interest in its dependency refs. Null on the dev/Mac path (no live values).</param>
     /// <param name="evaluator">The evaluator each child uses to compute its expression.</param>
-    public static Props Props(IActorRef publishActor, IActorRef? mux, IVirtualTagEvaluator evaluator) =>
-        Akka.Actor.Props.Create(() => new VirtualTagHostActor(publishActor, mux, evaluator));
+    /// <param name="historyWriter">Sink for results whose plan has <c>Historize=true</c>. Null ⇒
+    /// <see cref="NullHistoryWriter.Instance"/> (no durable historian wired), so existing call sites
+    /// compile unchanged and never historize.</param>
+    public static Props Props(IActorRef publishActor, IActorRef? mux, IVirtualTagEvaluator evaluator,
+        IHistoryWriter? historyWriter = null) =>
+        Akka.Actor.Props.Create(() => new VirtualTagHostActor(publishActor, mux, evaluator, historyWriter));
 
     /// <summary>Initializes a new instance of the <see cref="VirtualTagHostActor"/> class.</summary>
     /// <param name="publishActor">The OPC UA publish actor results are bridged to.</param>
     /// <param name="mux">Optional dependency multiplexer passed to each spawned child.</param>
     /// <param name="evaluator">The evaluator each child uses to compute its expression.</param>
-    public VirtualTagHostActor(IActorRef publishActor, IActorRef? mux, IVirtualTagEvaluator evaluator)
+    /// <param name="historyWriter">Sink for historized results; null ⇒ <see cref="NullHistoryWriter.Instance"/>.</param>
+    public VirtualTagHostActor(IActorRef publishActor, IActorRef? mux, IVirtualTagEvaluator evaluator,
+        IHistoryWriter? historyWriter = null)
     {
         ArgumentNullException.ThrowIfNull(publishActor);
         ArgumentNullException.ThrowIfNull(evaluator);
         _publishActor = publishActor;
         _mux = mux;
         _evaluator = evaluator;
+        _history = historyWriter ?? NullHistoryWriter.Instance;
 
         Receive<ApplyVirtualTags>(OnApply);
         Receive<VirtualTagActor.EvaluationResult>(OnResult);
@@ -154,6 +166,15 @@ public sealed class VirtualTagHostActor : ReceiveActor
 
         _publishActor.Tell(new OpcUaPublishActor.AttributeValueUpdate(
             nodeId, result.Value, OpcUaQuality.Good, result.TimestampUtc));
+
+        // Historize iff the plan opted in. Reuses _planByVtag (kept in lock-step with _children), so
+        // no parallel map. The historian path key is the SAME folder-scoped NodeId we just published
+        // to. For a computed value source == server, so both timestamps are the evaluation time.
+        if (_planByVtag.TryGetValue(result.VirtualTagId, out var plan) && plan.Historize)
+        {
+            _history.Record(nodeId, new DataValueSnapshot(
+                result.Value, 0u /* StatusCodes.Good */, result.TimestampUtc, result.TimestampUtc));
+        }
     }
 
     private void OnChildTerminated(Terminated msg)
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/ZB.MOM.WW.OtOpcUa.Runtime.csproj b/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/ZB.MOM.WW.OtOpcUa.Runtime.csproj
index c870ba65..98eb9cce 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/ZB.MOM.WW.OtOpcUa.Runtime.csproj
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/ZB.MOM.WW.OtOpcUa.Runtime.csproj
@@ -32,6 +32,9 @@
         <!-- IScriptLogPublisher lives in Core.Scripting; DpsScriptLogPublisher implements it
              here so the concrete Akka DPS routing stays out of the Core layer. -->
         <ProjectReference Include="..\..\Core\ZB.MOM.WW.OtOpcUa.Core.Scripting\ZB.MOM.WW.OtOpcUa.Core.Scripting.csproj"/>
+        <!-- IHistoryWriter / NullHistoryWriter live in Core.VirtualTags; VirtualTagHostActor forwards
+             historized VirtualTag results to it (H5c). The durable sink is wired by the host's DI. -->
+        <ProjectReference Include="..\..\Core\ZB.MOM.WW.OtOpcUa.Core.VirtualTags\ZB.MOM.WW.OtOpcUa.Core.VirtualTags.csproj"/>
     </ItemGroup>
 
 </Project>
diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/VirtualTags/VirtualTagHostActorTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/VirtualTags/VirtualTagHostActorTests.cs
index 43461e72..76bc7396 100644
--- a/tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/VirtualTags/VirtualTagHostActorTests.cs
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/VirtualTags/VirtualTagHostActorTests.cs
@@ -4,6 +4,8 @@ using Xunit;
 using ZB.MOM.WW.OtOpcUa.Commons.Engines;
 using ZB.MOM.WW.OtOpcUa.Commons.OpcUa;
 using ZB.MOM.WW.OtOpcUa.Commons.Types;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+using ZB.MOM.WW.OtOpcUa.Core.VirtualTags;
 using ZB.MOM.WW.OtOpcUa.OpcUaServer;
 using ZB.MOM.WW.OtOpcUa.Runtime.OpcUa;
 using ZB.MOM.WW.OtOpcUa.Runtime.Tests.Harness;
@@ -153,6 +155,71 @@ public sealed class VirtualTagHostActorTests : RuntimeActorTestBase
         secondChild.ShouldNotBe(firstChild);
     }
 
+    /// <summary>A plan with an explicit Historize flag, so H5c can assert the host historizes a
+    /// result iff the plan opted in. Mirrors <see cref="Plan"/> but threads <paramref name="historize"/>.</summary>
+    private static EquipmentVirtualTagPlan PlanH(
+        string vtagId, string equipmentId, string name, bool historize, string folderPath = "") =>
+        new(
+            VirtualTagId: vtagId,
+            EquipmentId: equipmentId,
+            FolderPath: folderPath,
+            Name: name,
+            DataType: "Double",
+            Expression: "ctx.GetTag(\"a\")",
+            DependencyRefs: new[] { "a" },
+            Historize: historize);
+
+    /// <summary>H5c: a result for a vtag whose plan has Historize=true is recorded with the
+    /// IHistoryWriter under the SAME folder-scoped NodeId the value was published to, carrying the
+    /// result value and OPC UA Good (0u) status — in addition to the normal publish.</summary>
+    [Fact]
+    public void Historized_vtag_result_is_recorded_with_the_history_writer()
+    {
+        var publish = CreateTestProbe();
+        var writer = new CapturingHistoryWriter();
+        var host = Sys.ActorOf(VirtualTagHostActor.Props(publish.Ref, mux: null, new StubEvaluator(), writer));
+
+        host.Tell(new VirtualTagHostActor.ApplyVirtualTags(
+            new[] { PlanH("vt-1", "eq-1", "speed-rpm", historize: true) }));
+
+        var ts = new DateTime(2026, 6, 7, 12, 0, 0, DateTimeKind.Utc);
+        host.Tell(new VirtualTagActor.EvaluationResult("vt-1", 42.0, ts, CorrelationId.NewId()));
+
+        // The publish still happens — historization is additive, not a replacement.
+        var update = publish.ExpectMsg<OpcUaPublishActor.AttributeValueUpdate>();
+        update.NodeId.ShouldBe("eq-1/speed-rpm");
+
+        // Wait for the history record to land (delivered on the same actor turn as the publish).
+        AwaitAssert(() => writer.Calls.Count.ShouldBe(1));
+        var (path, value) = writer.Calls[0];
+        path.ShouldBe("eq-1/speed-rpm");
+        value.Value.ShouldBe(42.0);
+        value.StatusCode.ShouldBe(0u); // OPC UA Good
+        value.SourceTimestampUtc.ShouldBe(ts);
+        value.ServerTimestampUtc.ShouldBe(ts);
+    }
+
+    /// <summary>H5c: a result for a vtag whose plan has Historize=false is NOT recorded — the writer
+    /// is never called — though the value is still published.</summary>
+    [Fact]
+    public void Non_historized_vtag_result_is_not_recorded()
+    {
+        var publish = CreateTestProbe();
+        var writer = new CapturingHistoryWriter();
+        var host = Sys.ActorOf(VirtualTagHostActor.Props(publish.Ref, mux: null, new StubEvaluator(), writer));
+
+        host.Tell(new VirtualTagHostActor.ApplyVirtualTags(
+            new[] { PlanH("vt-1", "eq-1", "speed-rpm", historize: false) }));
+
+        host.Tell(new VirtualTagActor.EvaluationResult("vt-1", 42.0, DateTime.UtcNow, CorrelationId.NewId()));
+
+        // The value is still published…
+        publish.ExpectMsg<OpcUaPublishActor.AttributeValueUpdate>();
+        // …but the historian was never touched.
+        publish.ExpectNoMsg(TimeSpan.FromMilliseconds(200));
+        writer.Calls.ShouldBeEmpty();
+    }
+
     /// <summary>A plan with an explicit Expression + DependencyRefs (the H1b in-place-change case).</summary>
     private static EquipmentVirtualTagPlan PlanWithRefs(
         string vtagId, string equipmentId, string name, string expression, params string[] refs) =>
@@ -277,6 +344,18 @@ public sealed class VirtualTagHostActorTests : RuntimeActorTestBase
         mux.LastSender.ShouldNotBe(firstChild);
     }
 
+    /// <summary>Capturing <see cref="IHistoryWriter"/>: records every Record call so H5c tests can
+    /// assert the host historizes (or does not) and with what path + snapshot.</summary>
+    private sealed class CapturingHistoryWriter : IHistoryWriter
+    {
+        public readonly List<(string Path, DataValueSnapshot Value)> Calls = new();
+
+        /// <summary>Captures the path + snapshot of a Record call.</summary>
+        /// <param name="path">The virtual tag path.</param>
+        /// <param name="value">The data value snapshot.</param>
+        public void Record(string path, DataValueSnapshot value) => Calls.Add((path, value));
+    }
+
     /// <summary>Deterministic no-op evaluator: keeps spawned children inert so tests drive the host's
     /// OnResult path directly via synthetic EvaluationResults.</summary>
     private sealed class StubEvaluator : IVirtualTagEvaluator