William of Rubruck or Guillaume de Rubrouck was a Flemish Franciscan missionary and explorer.
Voyage of William of Rubruck in 1253–1255
An initial from a 14th-century copy of the manuscript. The upper portion shows William of Rubruck and his travelling companion receiving a commission from Louis IX of France. The lower portion shows the two friars on their journey.
André de Longjumeau was a French diplomat and Dominican missionary and one of the most active Occidental diplomats in the East in the 13th century. He led two embassies to the Mongols: the first carried letters from Pope Innocent IV and the second bore gifts and letters from Louis IX of France to Güyük Khan. Well acquainted with the Middle East, he spoke Arabic and "Chaldean".
André went to Constantinople to obtain the crown of thorns bought by Louis IX from Baldwin II, Latin Emperor. It is preserved today in a 19th-century reliquary, in Notre-Dame de Paris.