1. Build up crannies so that your raider does not get resources out of you. 2. Send a polite request to the raider saying that you are not as active as he is, but you are also playing the game and would request him to stop raiding you. If he still does not agree, check if you can offer a tribute to him. 3. If you are a Gaul or a Roman, build up defences so that he loses troops when he pays you a visit.