William of Rubruck (circa 1220 - 1293) was a Flemish Franciscan missionary and explorer. His account is one of the masterpieces of medieval geographical literature comparable to that of Marco Polo. Born in Rubrouck, Flanders, he is known also as William of Rubruk, Willem van Ruysbroeck, Guillaume de Rubrouck or Willielmus de Rubruquis. A Flemish Franciscan monk, William had participated in the crusade of King Louis IX of France to Palestine and there heard about the Mongols from friar Andrew of Longjumeau, a Dominican who had been involved in papal diplomacy aimed at trying to enlist the Mongols in the Christian crusade against the Muslims. Rubruck then decided to undertake his own mission to the Mongols in the hope of promoting their conversion to Christianity. His roundtrip journey lasted the better part of three years. William had the distinction of being the first European to visit the Mongol capital of Karakorum on the Orhon River and return to write about it. In his report to King Louis IX titled "Itinerarium fratris Willielmi de Rubruquis de ordine fratrum Minorum, Galli, Anno gratia 1253 ad partes Orientales." (The Journey Of William Of Rubruck To The Eastern Parts Of The World) he provides a unique description of the Khan's palace and detail about the individuals of various ethnicities and religions whom he encountered.