[citation needed] He had close relations with the king of Cyprus, Henry I, acting as witness for two royal decrees; he was probably one of the king's executors named in a papal bull of Pope Alexander IV.

With his brother Baldwin of Ibelin, he led the Cypriot crusaders in the siege of Damietta in 1248.

[1] According to the medieval chronicler Jean de Joinville, he was one of the most accomplished knights of his generation and a benevolent ruler on Cyprus.

Many men then made confession to a brother of the Holy Trinity, named John, belonging to the retinue of count William of Flanders.

Then I crossed myself and knelt at the foot of a Saracen, who had a Danish axe in his hand, saying, "Thus was St Agnes killed."