<p>Horrible Histories returns for a special about King John and Magna Carta, starring Ben Miller. John annoys the Barons and agrees Magna Carta at Runnymede, after a banging rap battle. Meanwhile across the world we meet the formidable Genghis Khan in Mongolia, and catch up with the crafty Saladin during the Crusades. With of course, our host Rattus to guide the way!</p>