Constantine XI Dragases Palaiologos or Dragaš Palaeologus was the last reigning Byzantine emperor from 23 January 1449 until his death in battle at the fall of Constantinople on 29 May 1453. Constantine's death marked the definitive end of the Eastern Roman Empire, which traced its origin to Constantine the Great's foundation of Constantinople as the Roman Empire's new capital in 330.
Constantine was the fourth son of Emperor Manuel II Palaiologos and Serbian noblewoman Helena Dragaš. Little is known of his early life, but from the 1420s onward, he repeatedly demonstrated great skill as a military general. Based on his career and surviving contemporary sources, Constantine appears to have been primarily a soldier.