William Moseley , Anna Popplewell , Georgie Henley and Skandar Keynes play Peter , Susan , Lucy and Edmund , the four British children that had to go to the countryside during the Blitz , and there they find a wardrobe that leads to the fantasy world of Narnia . William Moseley , Anna Popplewell , Georgie Henley and Skandar Keynes play Peter , Susan , Lucy and Edmund , four British children evacuated during the Blitz to the countryside , who find a wardrobe that leads to the fantasy world of Narnia .