Game of Thrones has transformed from a cult TV show into the most successful television series ever. Some of that runaway global success is down to Kit Harington. His smouldering turn as Jon Snow in the series has made him one of our brightest stars. The character's death and resurrection earlier this year made headline news around the world. Andrew Marr caught up with Kit on stage in London where he is currently playing Doctor Faustus in a controversial version of Marlowe's classic play. Please subscribe HERE.