Frederick's army was not large. He could neither afford nor mount a lengthening campaign in the Holy Land. The Sixth Crusade would be one of negotiation. Frederick hoped that a token show of force, a threatening march down the coast, would be enough to convince al-Kamil to honor a proposed agreement that had been negotiated some years earlier. Al-Kamil was occupied with a siege in Damascus against his nephew an-Nasir Da’ud. He then agreed to cede Jerusalem to the Franks, along with a narrow corridor to the coast.

The treaty was concluded on 18 February 1229, and also involved a ten-year truce. In it, al-Kamil surrendered Jerusalem with the exception of some Muslim holy sites. Frederick also received Bethlehem and Nazareth, part of Sidon district, and Jaffa and Toron, dominating the coast. Frederick entered Jerusalem on 17 March 1229 and received the formal surrender of the city by al-Kamil's agent.