Umur Ghazi was a loyal ally and friend of Emperor
John Cantacuzenus of the
Byzantine Empire and provided him with material aid during his military campaigns, especially during the
Byzantine civil war of 1341–1347. He apparently sent 380 ships and 28,000 men to aid him in the conflict and besieged the city of
Demotika in Thrace, Greece. The emperor John reportedly mourned his death. At the height of its power, the
Beylik of Aydin possessed 350 ships and 15,000 men. Umur's preying on Christian shipping led to the declaration of the
Smyrniote crusades against him by
Pope Clement VI in 1343. In 1348, his fleet was destroyed by an allied fleet from Venice, the
Knights of Rhodes and
Cyprus. Umur was killed by a barrage of arrows, climbing the walls of
Smyrna Castle during a recapture attempt. His older brother Hızır Bey was appointed in his place. Modern
İzmir's district Gaziemir (Ghazi Emir) is named after him. ==Personality and appearance==