The Battle of Petroe, also known as the Battle of Hades, was fought on August 20, 1057 between the Byzantine imperial forces of Theodore, the Domestic of the Schools of the East, and the rebellious general Isaac I Komnenos, commander of the Byzantine field army in Anatolia. Komnenos had rebelled against Michael VI Stratiotikos (r. 1056–1057) and won over the allegiance of many leading generals, including Nikephoros Bryennios and Nikephoros III Botaneiates. After Komnenos was proclaimed emperor, the two armies clashed at Hades, near the city of Nicaea. Although the right wing of the army of Komnenos was routed, the left wing of Komnenos’s army, led by Katakalon Kekaumenos, routed the imperial right, reached and entered their camp, and destroyed the tents. Komnenos himself held firm in the c