Tommaso Ugi di Siena was a 14th-century Italian adventurer, native of the city ofSiena inItaly. He resided at the court of theMongolIlkhanid rulerOljeitu in thePersian capital ofTabriz, where he held the high position ofIldüchi, "Sword bearer", for Oljeitu.[1] Other adventurers, such asBuscarello de Ghizolfi orIsol the Pisan, are known to have played similar roles at the Mongol court. Hundreds such Western adventurers entered into the service of Mongol rulers.[2]
In 1307, Tommaso led a Mongol embassy sent by Oljeitu to European monarchs. This embassy encouragedPope Clement V to speak in 1307 of the strong possibility that the Mongols could remit theHoly Land to the Christians, and to declare that the Mongol embassy from Oljeitu "cheered him like spiritual sustenance".[3] Relations were quite warm: in 1307, the Pope namedJohn of Montecorvino the first Archbishop ofKhanbalik and Patriarch of the Orient.[4]
The embassy further promised the delivery of between 100,000 and 200,000 horses to the Crusaders upon their arrival in the Holy Land.[5]
European nations accordingly prepared a crusade, but were delayed. A memorandum drafted by the Grand Master of theKnights HospitallersGuillaume de Villaret about military plans for a Crusade envisaged a Mongol invasion of Syria as a preliminary to a Western intervention (1307/8).[6] A corps of Frankmangonel specialists is known to have accompanied the Ilkhanid army in the conquest ofHerat in 1307.[7]