Constantine XI Palaiologos was the last Byzantine Emperor, reigning from 1449 until his death in 1453. He was born on February 8, 1405, and was a member of the Palaiologos dynasty. His reign was marked by the fall of Constantinople, the capital of the Byzantine Empire, to the Ottoman Empire led by Sultan Mehmed II. During his rule, Constantine XI worked to strengthen the defenses of Constantinople and sought assistance from Western Europe, but help was limited. He became a symbol of resistance and bravery, famously fighting to defend the city until the end. His death marked the end of the Byzantine Empire.