All these attempts to mount a combined offensive between the Franks and Mongols were too little and too late. In May 1291, the city of Acre was conquered by the Egyptian Mamluks in the Siege of Acre. When Pope Nicholas IV learned of this, he wrote to Arghun, again asking him to be baptized and to fight against the Mamluks. But Arghun had died on , and Pope Nicholas died as well in March 1292, putting an end to their efforts towards combined action.