Battle of Petroe

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 centre, causing the imperial army to break and run, leaving the way open to Constantinople.

Background
The short reign of Michael VI Stratiotikos was plagued by internal dissension, as the new emperor proceeded to alienate the leading figures of the military aristocracy. Of the two most important, Katakalon Kekaumenos and Nikephoros Bryennios, Kekaumenos was the most popular general in the empire and the emperor’s decision to deprive him of his command at Antioch on charges of extortion did not sit well with the other leading nobles. But it was the emperor’s actions towards Nikephoros Bryennios that precipitated the rebellion.

His decision to restore Bryennios’s rank but not his estates or fortune confiscated by the empress Theodora, and insulting Bryennios to his face when he complained to Michael VI in person proved to be his undoing. Michael VI compounded his error by rebuffing Bryennios after he had already ordered the restored general to lead a division of 3,000 men to reinforce the army in Cappadocia. From here Bryennios began plotting to overthrow the emperor. On his arrival however, he attacked and beat a representative of the emperor who countermanded Nikephoros's orders before throwing him in prison, which his officers took as a sign that Nikephoros was about to rebel. Releasing the imprisoned officer, they captured Nikephoros, blinded him and sent him to Constantinople.

It was Bryennios' capture that precipitated the military nobility to rally around Isaac Komnenos. Fearing that their plot was about to be discovered, Isaac Komnenos was taken, apparently most unwillingly, by Romanos Skleros, Michael Bourtzes, Nikephoros Botaneiates and the sons of Romanos III Argyros to Gounaria where he was proclaimed emperor on 8 June 1057.

Initial moves
After Isaac Komnenos was raised to the purple, Kekaumenos forged an imperial order ordering him to march against the Seljuk chieftain Samouch with five tagmata. Of these, two were Frankish, one Russian, and two were Byzantine – those of Koloneia and Chaldia. Gathering his forces in the plain of Nikopolis, he joined up with what local troops Komnenos was able to gather, crossed the Sangarius river and took possession of Nicaea.

The Emperor Michael placed the imperial army under the command of Theodore, a court bureaucrat and eunuch who had been raised to the rank of Domestic of the Schools of the East. With him went the Bulgarian prince Aaron, the brother-in-law of Isaac Komnenos. Together they destroyed the bridges over the Sangarius River, hoping to cut off all communication for the rebel army from the provinces in which they had considerable family influence. From here they began approaching the city of Nicaea.

Isaac Komnenos was about 2 kilometres north of the city, and soon the two armies came into contact with each other. After some attempts were made to encourage the opposing armies to defect to the other, Komnenos ordered the ceasing of all communications between the two armies. Theodore, believing this to be a sign of weakness, advanced to Petroe, some 2.5 kilometres from Komnenos’s camp.

The battle
On August 20, 1057, Isaac Komnenos drew out his forces and arranged them for battle at a plain called, according to Michael Attaleiates, Polemon or Haidos. Kekaumenos commanded the left wing, Romanos Skleros the right, and Komnenos positioned himself in the centre. On the imperial side, Prince Aaron was stationed on the left wing, Basil Tarchaneiotes was positioned on the right, and the centre was commanded by Theodore the Eunuch. The battle itself was a game of two halves. The imperial left wing under Prince Aaron completely routed the rebel right wing. Pursuing their troops to the rebel camp, he proceeded to capture Romanos Skleros and was on the cusp of victory when he hesitated, unsure of his next move. Komnenos, on the verge of fleeing to Nicaea, was able to catch his breath and review what was happening on his left.

There, Kekaumenos had proceeded to rout the imperial Macedonian right, reaching and entering their camp, destroying the tents and killing the imperial generals Maurokatakalos and Katzamountes. This encouraged their own side while sowing doubt in the mind of Prince Aaron and his men. Isaac Komnenos managed to hold the centre firm long enough for Kekaumenos to join him and press in on Theodore. Here the battle was at its thickest, and Komnenos just managed to avoid being killed when he was attacked by four Russians. Eventually, however, the imperial centre began to give way and the imperial troops began fleeing the field. An important commander of the imperial forces, Radulph the Frank, was caught up in the ensuing rout when he caught a glimpse of Nikephoros Botaneiates leading an attacking division. Shouting a war cry, Radulph turned around and proceeded to attack Botaneiates, and the two engaged in single combat until Radulph’s sword broke and he was captured. Theodore and Prince Aaron fled to Constantinople, while Isaac Komnenos advanced to Nicomedia.

Aftermath
While at Nicomedia, Komnenos was met by envoys of the emperor, including Michael Psellos who offered him the title of Caesar if he would cease his rebellion. Although his proposals were publicly rejected, privately Isaac showed himself more open to negotiation, and he was promised the status of co-emperor. However, during the course of these secret negotiations, a riot in favor of Isaac broke out in Constantinople. The patriarch Michael Keroularios convinced Michael VI to abdicate in Isaac's favor on August 31, 1057.