William of Tripoli

In 1264, Urban issued three bulls—one to Louis IX and two to John of Valenciennes—that refer to William as the pope's "dear son" and identify him as a friar from Acre.

[8] Urban sent William back to the Holy Land as his nuncio (nuntius) to raise money there.

He praises William for "working for the benefit of the [Holy L]and, exposing his own person to dangers on land and sea.

[7] Two works in Latin are attributed to William: Written around 1271, the Notitia is only 33 pages long in a modern edition.

[13] It was written for Tedaldo Visconti, the future Pope Gregory X, whom William met in Acre shortly after Louis IX's failed crusade against Tunis in 1270.

[16] For its emphasis on conversion of Muslims, it has been called "a handbook for the Christian missionary on the history, law and beliefs of Islam.

"[17] It may have been written in response to Pope Gregory X's bull Dudum super generalis (11 March 1273), which asked for information on all the infidels that threatened Christendom.

[19] William's authorship of De statu has been questioned, with some scholars seeing it as a revised and expanded version of his Notitia, and probably the work of somebody else.