Born the daughter of a bearkeeper, Theodora began her career as an actress at an early age. She may also have been a courtesan, and she gave birth to at least one child out of wedlock. Converting to monophysitism, Theodora became a devout, if unorthodox, Christian, and for a time earned a living as a wool spinner.
Theodora impressed Justinian, nephew of the current emperor Justin I, with her beauty, wit and insight, and he made her his mistress and raised her to the rank of patrician. In 525 they were wed, and when Justinian ascended to the throne two years later, Theodora was proclaimed "augusta."
The empress exercised notable influence on her husband and on the workings of state. In addition to providing support and encouragement to Justinian, Theodora took part in making laws of the period (nearly all of which mention her name) and handled diplomatic functions ordinarily reserved for the emperor. She is famous for advising her husband to stand his ground during the Nika revolt, which he did successfully.
Theodora is well-known for sponsoring laws affecting women's rights in divorce, inheritance and guardianship, and prostitution; in particular, she saw to it that strict laws were passed preventing traffic in young girls. She also worked to mitigate laws against the monophysites, successfully ending their persecution, though never convincing Justinian to alter the official policy that favored Orthodoxy.
It is very difficult to gauge what achievements of Justinian's reign are owed to Empress Theodora, for the two worked together closely, and after her death Justinian showed a considerable decrease in activity. Theodora died at about age 50, probably from cancer.