Bardas Mamikonian was the regent (856-866) of Byzantine Emperor Michael III. Bardas was apparently the son of Marinos Mamikonian and the brother of Theodora, the wife of Byzantine Emperor Theophilus. Theodora and Theophilus were the parents of Michael III. With the death of Theophilus, young Michael accented to the thrown with the Regency of Empress Theodora and her two brothers, Bardas and Petronas the patrician.

Michael III (842-867), the son of Theophilus (emperor), was only 3 years old, when his father died. His education and instruction was not proper because the young emperor was neglected by his mother, Empress Theodora, and was influenced by his uncle, the logothetis Bardas (Vardas). As a result, Michael became salacious and debauchee, who entrusted the government to his capable uncle, Bardas, whose administration was marked by the missions of saints Cyril and Methodius to the Slavs.

On 849 Bardas together with logothetis Theoktistos initiated a far- reaching educational program and founded the University of Magnaura. It was during this regency that Leo the Mathematician, Photios who taught Greek Philosophy, and later Constantine-Cyril taught at the university. Among other professors were Theodoros who taught Geometry, Theodoghios, who taught Astronomy and Kometas who taught Greek Philology. In 856 Michael III came of age and not wanting to share running the government with Theoktistos, Bardas has him murdered.

After a failed attack on Bardas in 858 by Theodora, Bardas also has his sister and her daughters imprisoned in a nunnery; but Ignatius refused to tonsure them and was deposed for treason.