In the last year of her husband's reign (842) she overrode his ecclesiastical policy and summoned a council under the patriarch Methodius, in which the worship of images was finally restored and the iconoclastic clergy dispossessed. Appointed guardian of her infant son, Michael III, she carried on the government with a firm and judicious hand; she replenished the treasury and deterred the Bulgarians from an attempt at invasion.
In order to perpetuate her power she purposely neglected her son's education, and therefore must be held responsible for the voluptuous character which he developed under the influence of his uncle Bardas. Theodora endeavoured in vain to combat Bardas's authority; in 855 she was displaced from her regency at his prompting, and being subsequently convicted of intrigues against him was relegated to a monastery. She was sainted in recompense for her zeal on behalf of image-worship.