Once you start a game on a certain world, you will stay protected from hostile operations for two weeks.
No one will be able to attack your castles for that time. This includes castles you annex and conquer during these 2 weeks.
No one will be able to attack your castles for that time. This includes castles you annex and conquer during these 2 weeks.
There is one exception though. If you conquer other players castles, fortresses or cities while your beginners protection is active you will lose it and can be attacked from that point onwards.