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Constantine XI Dragases Palaiologos or Dragaš Palaeologus (Greek: Κωνσταντῖνος Δραγάσης Παλαιολόγος, Kōnstantinos Dragasēs Palaiologos; 8 February 1405 – 29 May 1453) was the last Byzantine Emperor from 6 January 1449 to 29 May 1453. He was son of Manuel II Palaiologos and Helena Dragas.