diff --git a/backend/controllers/falukantController.js b/backend/controllers/falukantController.js
index 0572543..a07f01d 100644
--- a/backend/controllers/falukantController.js
+++ b/backend/controllers/falukantController.js
@@ -92,6 +92,7 @@ class FalukantController {
             if (!result) throw { status: 404, message: 'No family data found' };
             return result;
         });
+        this.setHeir = this._wrapWithUser((userId, req) => this.service.setHeir(userId, req.body.childCharacterId));
         this.acceptMarriageProposal = this._wrapWithUser((userId, req) => this.service.acceptMarriageProposal(userId, req.body.proposalId));
         this.getGifts = this._wrapWithUser((userId) => {
             console.log('🔍 getGifts called with userId:', userId);
diff --git a/backend/migrations/add_is_heir_to_child_relation.sql b/backend/migrations/add_is_heir_to_child_relation.sql
new file mode 100644
index 0000000..5aa840f
--- /dev/null
+++ b/backend/migrations/add_is_heir_to_child_relation.sql
@@ -0,0 +1,9 @@
+-- Migration: Add is_heir column to child_relation table
+-- Date: 2025-12-08
+-- Description: Adds a boolean field to mark a child as the heir
+
+ALTER TABLE falukant_data.child_relation
+ADD COLUMN IF NOT EXISTS is_heir BOOLEAN DEFAULT false;
+
+COMMENT ON COLUMN falukant_data.child_relation.is_heir IS 'Marks whether this child is set as the heir';
+
diff --git a/backend/routers/falukantRouter.js b/backend/routers/falukantRouter.js
index 9f998b9..802b535 100644
--- a/backend/routers/falukantRouter.js
+++ b/backend/routers/falukantRouter.js
@@ -38,6 +38,7 @@ router.get('/director/:branchId', falukantController.getDirectorForBranch);
 router.get('/directors', falukantController.getAllDirectors);
 router.post('/directors', falukantController.updateDirector);
 router.post('/family/acceptmarriageproposal', falukantController.acceptMarriageProposal);
+router.post('/family/set-heir', falukantController.setHeir);
 router.get('/family/gifts', falukantController.getGifts);
 router.get('/family/children', falukantController.getChildren);
 router.post('/family/gift', falukantController.sendGift);
diff --git a/backend/services/falukantService.js b/backend/services/falukantService.js
index e685032..ba31ce2 100644
--- a/backend/services/falukantService.js
+++ b/backend/services/falukantService.js
@@ -2391,11 +2391,13 @@ class FalukantService extends BaseService {
             for (const rel of allRels) {
                 const kid = rel.child;
                 children.push({
+                    childCharacterId: kid.id,
                     name: kid.definedFirstName?.name || 'Unknown',
                     gender: kid.gender,
                     age: calcAge(kid.birthdate),
-            hasName: rel.nameSet,
-            _createdAt: rel.createdAt,
+                    hasName: rel.nameSet,
+                    isHeir: rel.isHeir || false,
+                    _createdAt: rel.createdAt,
                 });
             }
         }
@@ -2426,6 +2428,46 @@ class FalukantService extends BaseService {
         return family;
     }
 
+    async setHeir(hashedUserId, childCharacterId) {
+        const user = await this.getFalukantUserByHashedId(hashedUserId);
+        if (!user) throw new Error('User not found');
+        const character = await FalukantCharacter.findOne({ where: { userId: user.id } });
+        if (!character) throw new Error('Character not found for this user');
+
+        // Prüfe, ob das Kind wirklich ein Kind des aktuellen Charakters ist
+        const childRelation = await ChildRelation.findOne({
+            where: {
+                childCharacterId: childCharacterId,
+                [Op.or]: [
+                    { fatherCharacterId: character.id },
+                    { motherCharacterId: character.id }
+                ]
+            }
+        });
+
+        if (!childRelation) {
+            throw new Error('Child not found or not your child');
+        }
+
+        // Setze alle anderen Kinder des gleichen Elternteils auf isHeir = false
+        await ChildRelation.update(
+            { isHeir: false },
+            {
+                where: {
+                    [Op.or]: [
+                        { fatherCharacterId: character.id },
+                        { motherCharacterId: character.id }
+                    ]
+                }
+            }
+        );
+
+        // Setze das ausgewählte Kind als Erben
+        await childRelation.update({ isHeir: true });
+
+        return { success: true, childCharacterId };
+    }
+
     async getPossiblePartners(requestingCharacterId) {
         const proposals = await MarriageProposal.findAll({
             where: {
diff --git a/frontend/src/i18n/locales/de/falukant.json b/frontend/src/i18n/locales/de/falukant.json
index 8666698..7b95168 100644
--- a/frontend/src/i18n/locales/de/falukant.json
+++ b/frontend/src/i18n/locales/de/falukant.json
@@ -405,6 +405,11 @@
                 "title": "Kinder",
                 "name": "Name",
                 "age": "Alter",
+                "heir": "Erbe",
+                "isHeir": "Erbe",
+                "setAsHeir": "Als Erben festlegen",
+                "heirSetSuccess": "Das Kind wurde erfolgreich als Erbe festgelegt.",
+                "heirSetError": "Fehler beim Festlegen des Erben.",
                 "actions": "Aktionen",
                 "none": "Keine Kinder vorhanden.",
                 "detailButton": "Details anzeigen",
diff --git a/frontend/src/i18n/locales/en/falukant.json b/frontend/src/i18n/locales/en/falukant.json
index b83bd34..93eb587 100644
--- a/frontend/src/i18n/locales/en/falukant.json
+++ b/frontend/src/i18n/locales/en/falukant.json
@@ -201,6 +201,23 @@
                 "councillor": "Councillor",
                 "assessor": "Assessor"
             }
+        },
+        "family": {
+            "children": {
+                "title": "Children",
+                "name": "Name",
+                "age": "Age",
+                "heir": "Heir",
+                "isHeir": "Heir",
+                "setAsHeir": "Set as Heir",
+                "heirSetSuccess": "The child has been successfully set as heir.",
+                "heirSetError": "Error setting heir.",
+                "actions": "Actions",
+                "none": "No children available.",
+                "detailButton": "Show Details",
+                "addChild": "Add Child",
+                "baptism": "Baptize"
+            }
         }
     }
 }
\ No newline at end of file
diff --git a/frontend/src/views/falukant/FamilyView.vue b/frontend/src/views/falukant/FamilyView.vue
index 121ab3a..13d2d45 100644
--- a/frontend/src/views/falukant/FamilyView.vue
+++ b/frontend/src/views/falukant/FamilyView.vue
@@ -117,6 +117,7 @@
                             <tr>
                                 <th>{{ $t('falukant.family.children.name') }}</th>
                                 <th>{{ $t('falukant.family.children.age') }}</th>
+                                <th>{{ $t('falukant.family.children.heir') }}</th>
                                 <th>{{ $t('falukant.family.children.actions') }}</th>
                             </tr>
                         </thead>
@@ -130,6 +131,12 @@
                                         }}</button>
                                 </td>
                                 <td>{{ child.age }}</td>
+                                <td>
+                                    <span v-if="child.isHeir" class="heir-badge">{{ $t('falukant.family.children.isHeir') }}</span>
+                                    <button v-else-if="child.hasName" @click="setAsHeir(child)" class="set-heir-button">
+                                        {{ $t('falukant.family.children.setAsHeir') }}
+                                    </button>
+                                </td>
                                 <td>
                                     <button @click="showChildDetails(child)">
                                         {{ $t('falukant.family.children.detailButton') }}
@@ -241,6 +248,23 @@ export default {
             console.log('Show details for child:', child);
         },
 
+        async setAsHeir(child) {
+            if (!child.childCharacterId) {
+                console.error('Child character ID missing');
+                return;
+            }
+            try {
+                await apiClient.post('/api/falukant/family/set-heir', {
+                    childCharacterId: child.childCharacterId
+                });
+                await this.loadFamilyData();
+                this.$root.$refs.messageDialog?.open('tr:falukant.family.children.heirSetSuccess');
+            } catch (error) {
+                console.error('Error setting heir:', error);
+                this.$root.$refs.errorDialog?.open('tr:falukant.family.children.heirSetError');
+            }
+        },
+
         formatCost(value) {
             return new Intl.NumberFormat(navigator.language, { minimumFractionDigits: 2, maximumFractionDigits: 2 }).format(value);
         },
@@ -457,4 +481,28 @@ h2 {
     height: 100%;
     transition: width 0.3s ease, background-color 0.3s ease;
 }
+
+.heir-badge {
+    display: inline-block;
+    padding: 4px 8px;
+    background-color: #4CAF50;
+    color: white;
+    border-radius: 4px;
+    font-size: 0.9em;
+    font-weight: bold;
+}
+
+.set-heir-button {
+    padding: 4px 8px;
+    background-color: #2196F3;
+    color: white;
+    border: none;
+    border-radius: 4px;
+    cursor: pointer;
+    font-size: 0.9em;
+}
+
+.set-heir-button:hover {
+    background-color: #1976D2;
+}
 </style>
\ No newline at end of file