Theodora, sometimes called Theodora the Armenian or Theodora the Blessed, was Byzantine empress as the wife of Byzantine emperor Theophilos from 830 to 842 and regent for the couple's young son Michael III, after the death of Theophilos, from 842 to 856. She is sometimes counted as an empress regnant, who actually ruled in her own right, rather than just a regent. Theodora is most famous for bringing an end to the second Byzantine Iconoclasm (814–843), an act for which she is recognized as a saint in the Eastern Orthodox Church. Though her reign saw the loss of most of Sicily and failure to retake Crete, Theodora's foreign policy was otherwise highly successful; by 856, the Byzantine Empire had gained the upper hand over both the Bulgarian Empire and the Abbasid Caliphate, and the Slavic tribes in the Peloponnese had been forced to pay tribute, all without decreasing the imperial gold reserve.

Theophilos was the Byzantine Emperor from 829 until his death in 842. He was the second emperor of the Amorian dynasty and the last emperor to support iconoclasm. Theophilos personally led the armies in his long war against the Arabs, beginning in 831.