The first Roman empress to rule as regent was Irene of Athens. She ruled for just five years, from 797 to 802 A.D. She was a controversial empress and had a major impact on the religious practices and foreign policies of the Eastern Roman (Byzantine) Empire.
Irene was born in 752 to a noble Athenian family. In 769, she was married to Leo IV, the son of Constantine V, ruler of the Eastern Empire. About a year later, they had a son.
When Constantine V died in 775, Leo IV became emperor, and Irene was the empress consort. During his rule, Leo exiled his half-brothers, who tried to challenge him for the throne. He died in September of 780 while battling the Caliph Al-Mahdi’s armies.
At the time of Leo’s death, his son was only nine years old, so Irene ruled as regent. Six weeks later, her late husband’s half-brothers attempted to come for the throne again.
Irene uncovered the plot and had them ordained into the priesthood, making them ineligible for succession.
In 780, Irene arranged a marriage between her son and the daughter of Frankish King Charlemagne, Rotrude. She also played a part in restoring the veneration of images. She and her son signed the document for this law on October 23, 787, reuniting the Eastern church with the church of Rome.
That same year, Irene ended her son’s marriage to the daughter of Charlemagne and selected Maria of Amnia instead. When her son turned 16 in 790, Irene was expected to hand over authority to him, but she refused to let go of her power.
As a result, there was a military revolt against her. Her son managed to take full power as emperor, but Irene remained as empress.
In 797, Irene conspired with her network of supporters to regain full power for herself. Her son tried to flee the capital, but he was captured and brought back to Constantinople.

Sign up for Chip Chick’s newsletter and get stories like this delivered to your inbox.
Irene personally gave the order to have her own son blinded by gouging out his eyes. By removing her son as a threat, she was able to secure the throne for herself.
It’s unclear exactly when her son died. He may have died shortly after his eyes were gouged out, or lived a quiet life with his mistress.
In 799, Irene’s late husband’s half-brothers attempted another uprising, but they were exiled and blinded. In 800, Irene was deposed because Pope Leo III would not support a woman as ruler.
By law, women could not lead the army or occupy the throne. So, the pope declared the throne vacant and named Charlemagne as emperor on Christmas Day.
Apparently, Irene tried to arrange a marriage between herself and Charlemagne, but her plan failed. Government officials rebelled against Irene in 803, and she was exiled to the Greek island of Lesbos, where she spun wool for a living until she died the following year. The Byzantines did not recognize Charlemagne as emperor until 814.