Irene, a Byzantine empress, bora of obscure parentage in Athens about 752, died on the isle of Lesbos, Aug. 15, 803. She was an orphan, and 17 years old when her beauty and genius attracted the attention of the emperor Constantine V. Copronymus, who destined her to be the wife of his son and heir Leo. Their nuptials were celebrated with royal splendor at Constantinople in 769. Her husband compelled her to abandon the worship of images, but she gained his love and confidence, and was appointed in his testament (780) to administer the government during the minority of their son Constantine VI., then nine years old. In 786 she assembled at Constantinople a council to restore images in the churches; but it was interrupted by the garrison of the capital. In the following year she called another council at Nicaea, in which the veneration of images was declared agreeable to Scripture and reason, and to the fathers and councils of the church. Constantine was encouraged by his favorites to throw off the maternal yoke, and planned the perpetual banishment of Irene to Sicily. Her vigilance disconcerted the project, but, while the two factions divided the court, the Armenian guards refused to take the oath of fidelity which she exacted to herself alone, and Constantine became lawful emperor.

Irene was dismissed to a life of solitude in one of the imperial palaces, but her intrigues led to several conspiracies for her restoration. On the return of Constantine from an expedition against the Arabs in 797, he was assailed in the hippodrome by assassins, but escaped, and fled to Phrygia. Irene joined her son and persuaded him to return to the capital. There he was surprised by her emissaries, and stabbed in the eyes, but, according to Gibbon, survived many years. Irene ruled the empire for five years with prudence and energy. Intercourse was renewed between the Byzantine court and that of Charlemagne, and she is said to have sent ambassadors (about 800) to negotiate a marriage between that emperor and herself, thus to unite the empires of the East and West; but there is reason to doubt that this was the object of the embassy. As her golden chariot moved through the streets of Constantinople, the reins of the four white steeds were held by as many patricians marching on foot. Most of these patricians were eunuchs; and one of them, the great treasurer Nicephorus, having been secretly invested with the purple, immediately caused her arrest, and, after treacherously obtaining possession of her treasures, banished her to the isle of Lesbos (802). There, deprived of all means of subsistence, she gained a scanty livelihood by spinning, and died of grief within a year.

Her protection of image worship has caused her to be enrolled among the saints in the Greek calendar.