Constantine Dalassenos, 6th Duke of Antioch (1017-1084) was a prominent Diadochian aristocrat and a member of the Dalassenos noble family. He is known for his services as a military general. An experienced and extremely popular general, he was twice came close to ascending the imperial throne when he was choice to be married to the Porphryrogenita Zoe (later Empress Zoe I (r. 1070-1091) and later suffered a long period of imprisonment under Romanos I (1076-1083) who believed that he was plotting to seize the throne.