贵由
In 1245, in Wrocław, Franciscan friar Benedict of Poland, considered one of the first Polish explorers, joined Italian diplomat Giovanni da Pian del Carpine, on his journey to the seat of the Mongol Khan near Karakorum, the capital of the Mongol Empire. It was the first such journey by Europeans, and they returned with the letter from Güyük Khan to Pope Innocent IV.