Irene of Athens was a Byzantine empress who rose from a noble Greek family to become a powerful political leader. After marrying Emperor Leo IV, she served as regent for her son, Constantine VI, and later ruled the Byzantine Empire as the sole empress regnant from 797 to 802. She is most significant for her role in ending the first period of iconoclasm by convening the Second Council of Nicaea in 787, which restored the veneration of religious icons.