Mongol Derby Prior-Palmer , five-year , is youngest winner of Briton Lara . The fearsome Genghis Khan , leader of the Mongols between 1162 and 1227 , established and expanded the `` Ortoo . '' Race recognized by Ortoo as the world 's lengthiest . Race takes inspiration from Edinburgh pioneering postal service . `` This is no guided tour , or pony trek , '' says race website .
Mongol Derby Prior-Palmer , five-year , is youngest winner of Briton Lara . Race recognized by Ortoo as the world 's lengthiest . Race takes inspiration from Edinburgh pioneering postal service . `` This is no guided tour , or pony trek , '' says race website .