Battle of Pegae

The attempts of the Bulgarian emperor Simeon I to negotiate a joint Bulgarian–Arab assault on the city with the Fatimids were uncovered by the Byzantine and countered.

Although the Byzantine–Bulgarian conflict that began in 913 was provoked by the Byzantines, it was the Bulgarian monarch Simeon I (r. 893–927) who was seeking pretext to wage war and fulfil his ambitions to claim an imperial title for himself and to assume the throne of Constantinople.

[4][5] However, in 919 Admiral Romanos Lekapenos married his daughter to Constantine VII and in 920 proclaimed himself senior emperor, ruining Simeon I's ambitions to ascend the throne by diplomatic means.

Thus, in the beginning of 921 Simeon I did not reply to a proposal of the Ecumenical Patriarch Nicholas Mystikos to betroth one of his daughters or sons to a progeny of Romanos I and sent his army into Byzantine Thrace, reaching Katasyrtai in the outskirts of Constantinople.

[6][7][8] Romanos I retaliated with a campaign under Pothos Argyros, who reached the town of Aquae Calidae, near modern Burgas, but part of his army was ambushed and destroyed by the Bulgarians.

[6][12][15] After the battle, the Bulgarians burned the palaces in Pegae and looted the area north of the Golden Horn waterway on the opposite shore of the walls of Constantinople.

Before leaving the capital, Preslav, Simeon I sent a letter to Patriarch Nicholas Mystikos in which he rebuffed the proposal for a dynastic marriage with the family of Romanos I.

[16][17] The Bulgarian monarch denied the accusations of Mystikos that he was responsible for the terrible war and instead blamed the eunuchs of Empress Zoe Karbonopsina, who had rebuffed his proposal to betroth his daughter to Constantine VII in 914 and had attacked Bulgaria in 917.

[6][21] In 922, the Bulgarians renewed their offensive in Thrace to divert the Byzantines from the clandestine negotiations with the Fatimid Caliphate to form a Bulgarian–Arab alliance for a joint assault of Constantinople.