diff --git a/backend/src/main/java/org/raddatz/familienarchiv/timeline/EventType.java b/backend/src/main/java/org/raddatz/familienarchiv/timeline/EventType.java
new file mode 100644
index 00000000..f392f3c5
--- /dev/null
+++ b/backend/src/main/java/org/raddatz/familienarchiv/timeline/EventType.java
@@ -0,0 +1,17 @@
+package org.raddatz.familienarchiv.timeline;
+
+/**
+ * Kind of a curated {@link TimelineEvent}.
+ *
+ * <p>The string value names are a <strong>stable frontend styling contract</strong>: the
+ * Svelte timeline components hard-code {@code "PERSONAL"} (family accent) and
+ * {@code "HISTORICAL"} (muted world accent) as Tailwind class-map keys. There is no
+ * mapping layer — renaming either value requires a coordinated frontend change. See
+ * ADR-040.
+ */
+public enum EventType {
+    /** A family/personal event (birth, wedding, move) — rendered with the family accent. */
+    PERSONAL,
+    /** A world/historical event providing context — rendered with the muted world accent. */
+    HISTORICAL
+}