Irene of Athens, surname Sarantapechaena, was Byzantine empress consort to Emperor Leo IV from 775 to 780, regent during the childhood of their son Constantine VI from 780 until 790, co-ruler from 792 until 797, and finally empress regnant and sole ruler of the Eastern Roman Empire from 797 to 802. A member of the politically prominent Sarantapechos family, she was selected as Leo IV's bride for unknown reasons in 768. Even though her husband was an iconoclast, she harbored iconophile sympathies. During her rule as regent, she called the Second Council of Nicaea in 787, which condemned iconoclasm as heretical and brought an end to the first iconoclast period (730–787). Her public figure was very polarizing during her 5 year reign, as most saw it as wrong for a woman to rule solely. Her reign as such made her the first ever empress regnant, ruling in her own right, in Roman and Byzantine imperial history.

Constantine VI was Byzantine emperor from 780 to 797. The only child of Emperor Leo IV, Constantine was named co-emperor with him at the age of five in 776 and succeeded him as sole Emperor in 780, aged nine. His mother Irene exercised control over him as regent until 790, assisted by her chief minister Staurakios. The regency ended when Constantine reached maturity, but Irene sought to remain an active participant in the government. After a brief interval of sole rule Constantine named his mother empress in 792, making her his official colleague.