diff --git a/geneit_app/src/utils/family_tree.ts b/geneit_app/src/utils/family_tree.ts
index ec53aa1..e9dba4d 100644
--- a/geneit_app/src/utils/family_tree.ts
+++ b/geneit_app/src/utils/family_tree.ts
@@ -1,5 +1,5 @@
 import { Couple, CouplesList } from "../api/CoupleApi";
-import { Member, MembersList } from "../api/MemberApi";
+import { Member, MembersList, dateTimestamp } from "../api/MemberApi";
 
 export interface CoupleInformation {
   couple: Couple;
@@ -67,13 +67,25 @@ export function buildDescendingTree(
     member_couples.push({
       couple: c,
       member: pair!,
-      down: c_children.map((c) => buildDescendingTree(c.id, members, couples)),
+      down: sortChildren(
+        c_children.map((c) => buildDescendingTree(c.id, members, couples))
+      ),
     });
   }
 
   return {
     member: member,
-    down: children.map((c) => buildDescendingTree(c.id, members, couples)),
+    down: sortChildren(
+      children.map((c) => buildDescendingTree(c.id, members, couples))
+    ),
     couples: member_couples,
   };
 }
+
+function sortChildren(n: FamilyTreeNode[]): FamilyTreeNode[] {
+  n.sort(
+    (a, b) =>
+      dateTimestamp(a.member.dateOfBirth) - dateTimestamp(b.member.dateOfBirth)
+  );
+  return n;
+}