Battle of Petroe

Battle of Petroe
Date 20 August 1057 Location Plain of Ha[i]des, near Nicaea 40°29′13″N 29°41′26″E / 40.48694°N 29.69056°E / 40.48694; 29.69056 Result Rebel victory
Belligerents
Imperial forces of Michael VI Stratiotikos	Rebel forces of Isaac I Komnenos
Commanders and leaders
Theodore Aaron Basil Tarchaneiotes	Isaac I Komnenos Katakalon Kekaumenos Romanos Skleros
Casualties and losses
Heavy	Significant
class=notpageimage| Approximate location within modern Turkey

The Battle of Petroe,^[1] also known as the Battle of Hades,^[2] was fought on 20 August 1057 between two rival Byzantine armies: the loyalist forces of the Byzantine emperor Michael VI Stratiotikos (r. 1056–1057) under the proedros Theodore, and the supporters of the rebel general Isaac Komnenos.

Disgruntled by the neglect of army finances and the Emperor's unwillingness to consider their grievances, Komnenos and other leading commanders, including Nikephoros Bryennios and Nikephoros Botaneiates, began plotting against Michael VI, and on 8 June 1057, Komnenos was proclaimed emperor at his estates in Cappadocia. After his supporters rallied regiments from Anatolia to his cause, his army marched west towards Constantinople, and encountered the loyalist army, composed largely of regiments from Europe, near the city of Nicaea.

After confronting each other for several days, the two armies finally engaged at the plain of Hades. Although the right wing of the rebel army was beaten, Komnenos himself held firm in the centre. Victory was won by his left wing, led by Katakalon Kekaumenos, which routed the imperial right, reached and entered their camp, and destroyed their tents, causing the imperial army to break and run, leaving the way open to Constantinople. With the rebel army approaching the capital, Michael VI offered Komnenos the position of Caesar and heir-apparent, but he was quickly convinced to abdicate the throne. On the next day, 1 September 1057, Isaac Komnenos was crowned emperor in Constantinople. His reign was marked by his unsuccessful attempts to reform the administration and strengthen the empire, but the opposition he aroused led to his own abdication in November 1059.