Dei patris immensa was a letter written by Pope Innocent IV to the Mongols (the Pope also wrote other letters to the Mongols, which are known as Cum non solum and Viam agnoscere veritatis). It was written on March 5, 1245, was an exposition of the Christian faith, and urged Mongols to accept baptism.[1] It was intended to be carried by the Franciscan friar and papal envoy Laurentius of Portugal.[2] However, nothing more is known about Laurentius' embassy, and it is possible that he never actually left.[3]