When you start a new game in Civilization War, a guest account is created automatically.
However, guest account data is not backed up or saved anywhere but in your device, and thus it will be erased in case you remove the application or reinstall it.
Such data is deleted permanently and cannot be restored, so we highly recommend synchronizing your account with one of the networks available.
To do so, simply follow the below procedure:
Press Lord avatar in the top left corner of the Castle screen → Settings → Sync Account → press Sync Account button in the bottom left corner → choose your preferred way of synchronization