Ruysbroek (Or Rubruquis), Willem De,
a mediaeval traveller and missionary, was born in Brabant about 1220. In 1253 Louis IX of France sent him and two other friars to Tartary. The object of their mission was to propagate Christianity among the Tartars, to search for Prester John, and to visit Sartach, a Tartar chief, who was reported to be a Christian. Ruysbroek performed this arduous enterprise bravely, and, returning through Persia and Asia Minor, reached home in August, 1255. He died after 1256. He wrote a work, which is divided into two parts, De Gestis (or De Moribus) Tartartorum, and Itinerarium Orientis. Hakluyt published one part in his Principal Navigations (Lond. 1598-1606, 3 vols. fol.); but the story of Ruysbroek is found most complete in Purchas's Pilgrims (1626, 4 vols. fol.). — Hoefer, Nouv. Biog. Gé né rale, s.v.