 In a letter dated 20 September 1300 from Pope Boniface to the Archbishop of Nicosia, Isol was titled "Vicar of Syria and the Holy Land for Ghazan the Emperor of the Tartars", suggesting that he was put in charge of coordinating relations between the Crusader states and the Mongols.Isol is also a probable source for some of the information about Europe in the "History of the World" chronicle by the Mongol historian Rashid-al-Din Hamadani.In 1300, Isol acted as an intermediary between Ghazan and European leaders such as Henry II of Cyprus and Pope Boniface VIII.