Between 920 and 922, Bulgaria increased its pressure on Byzantium, campaigning in the west through Thessaly, reaching the Isthmus of Corinth, and in the east in Thrace, reaching and crossing the Dardanelles to lay siege on the town of Lampsacus. Simeon's forces appeared before Constantinople in 921, when they demanded the deposition of Romanos and captured Adrianople; in 922 they were victorious at Pigae, burning much of the Golden Horn and seizing Bizye.

The Battle of Pegae was fought in the outskirts of Constantinople between the forces of the Bulgarian Empire and the Byzantine Empire during the Byzantine–Bulgarian war of 913–927. The battle took place in a locality called Pegae (i.e. "the spring"), named after the nearby Church of St. Mary of the Spring. The Byzantine lines collapsed at the very first Bulgarian attack and their commanders fled the battlefield. In the subsequent rout most Byzantine soldiers were killed by the sword, drowned or were captured.