The Latin historian William of Tyre described John as short and unusually ugly, with eyes, hair and complexion so dark he was known as 'the Moor'. Yet despite his physical appearance, John was known as Kaloioannes, "John the Good" or "John the Beautiful". The epithet referred not to his body but to his character. Both his parents had been unusually pious and John surpassed them. Members of his court were expected to restrict their conversation to serious subjects only. The food served at the emperor's table was very frugal and John lectured courtiers who lived in excessive luxury. His speech was dignified, but he engaged in repartee on occasion and his seriousness did not exclude a sense of humour. As a father he was affectionate, though he demanded high standards from his children, and he was a faithful husband to his wife. Despite his personal austerity, John had a high conception of the imperial role and would appear in full ceremonial splendour when this was advantageous. He was highly respected and honoured by his subjects.
John was famed for his piety and his remarkably mild and just reign. He is an exceptional example of a moral ruler, at a time when cruelty was the norm. He is reputed never to have condemned anyone to death or mutilation. Charity was dispensed lavishly. For this reason, he has been called the Byzantine Marcus Aurelius. By the example of his personal purity and piety he effected a notable improvement in the manners of his age. Descriptions of him and his actions indicate that he had great self-control and personal courage, was an excellent strategist and an expert imperator in the field, and through his many campaigns he devoted himself to the preservation of his empire.
John II succeeded his father as ruling basileus in 1118, but had already been proclaimed co-emperor by Alexios I on September 1, 1092. Niketas Choniates alone tells of the actions by which John II secured his own accession to power. Alexios I had favoured John to succeed him over his wife Irene's favourite, the Caesar Nikephoros Bryennios, who was married to their daughter Anna Komnena. Alexios resorted to dissimulation in order to avert Irene's criticism of his choice and her demands that Nikephoros should succeed. As Alexios lay on his deathbed in the monastery of the Mangana on 15 August 1118, John, consorting with relatives whom he could trust, among whom was his brother, the sebastokrator Isaac Komnenos, stole into the monastery and took the imperial signet ring from his dying father. Then, taking up arms, he rode to the Great Palace, gathering the support of the citizenry who acclaimed him emperor. Irene was taken by surprise and was unable either to persuade her son to desist, or to induce Nikephoros to act against him. Although the palace guard at first refused to admit John without proof of his father's wishes, the mob surrounding the new emperor simply forced entry.
Alexios died the following night. John refused to join the funeral procession, in spite of his mother's urging, because his hold on power was so tenuous. However, in the space of a few days, his position seemed secure. Within a year of his accession, however, John II uncovered a conspiracy to overthrow him which implicated his mother and sister. Anna's husband Nikephoros had little sympathy with her ambitions, and it was his lack of support which doomed the conspiracy. Anna was stripped of her property, which was offered to the emperor's friend John Axouch. Axouch wisely declined and his influence ensured that Anna's property was eventually returned to her and that John II and his sister became reconciled, at least to a degree. Irene retired to a monastery and Anna seems to have been effectively removed from public life, taking up the less active occupation of historian. However, Nikephoros remained on good terms with his brother-in-law. To safeguard his own succession, John crowned his young son Alexios co-emperor in 1122.
The family intrigues that challenged his succession to the throne probably contributed to John's approach to rulership, which was to appoint men from outside the imperial family to help him govern the empire. This was a radical departure from the methods of his father, who had used the imperial family and its many connections to fill almost all senior administrative and military posts.
John Axouch was John II's closest adviser and was his only intimate friend. Axouch was a Turk captured as a child at the Siege of Nicaea, who had been given as a gift to John's father. Emperor Alexios had thought him a good companion for his son, and so he had been brought up alongside the prince in the imperial household. Axouch was immediately appointed Grand Domestic (in Greek: μέγας δομέστικος, megas domestikos), upon the accession of John II. The Grand Domestic was the commander in chief of the Byzantine armies. It has been suggested that references to Axouch's possession of the imperial seal early in the reign of John's successor Manuel I meant that he was, in addition to his military duties, the head of the civil administration of the Empire. This was an unofficial position known at the time as the mesazon, and equivalent to a vizier or 'prime-minister.' Such an appointment was remarkable, and a radical departure from the nepotism that had characterised the reign of Alexios I. The imperial family harboured some degree of resentment at this decision, which was reinforced by the fact that they were required to make obeisance to John Axouch whenever they met him.
The emperor had complete confidence in his appointees, many of whom had been chosen on merit rather than their connection to the imperial family and related aristocratic clans. John's unwillingness to allow his family to interfere too much in his government was to remain constant for the rest of his reign. John appointed a number of his father's personal retainers to high office, men such as Eustathios Kamytzes, Michaelitzes Styppeiotes and George Dekanos. These were men who had been politically eclipsed during the ascendancy exercised by John's mother in the later years of the reign of Alexios I. A number of 'new men' were raised to prominence by John II, these included Gregory Taronites, Manuel Anemas and Theodore Vatatzes, the latter two also became his sons-in-law.
Despite his move away from close reliance on the imperial family and its connections, John's court and government had many similarities to that of his father, not least in its serious tone and piety. Indeed, an extant collection of political advice couched in poetic form, called the Mousai, are attributed to Alexios I. The Mousai are addressed directly to John II and exhort him, amongst other things, to maintain justice during his reign and a full treasury. Alexios' advice on rulership therefore continued to be available to his son, even after the old emperor's death.
The increase in military security and economic stability within Byzantine western Anatolia created by John II's campaigns allowed him to begin the establishment of a formal provincial system in these regions. The theme (province) of Thrakesion was re-established, with its administrative centre at Philadelphia. A new theme, named Mylasa and Melanoudion, was created to the south of Thrakesion.
The central tenet of the foreign policy of John II in the West was to maintain an alliance with the German emperors (Holy Roman Empire). This was necessary to limit the threat posed by the Normans of southern Italy to Byzantine territory in the Balkans. This threat became especially acute after Roger II of Sicily made himself supreme in southern Italy and assumed the title of king. Emperor Lothair III had Byzantine backing, including a large financial subsidy, for his invasion of Norman territory in 1136, which reached as far south as Bari. Pope Innocent II, with the Church's possessions in Italy under threat by Roger II, who supported Antipope Anacletus II, was also party to the alliance of Lothair and John II. However, this alliance proved unable to resist Roger, who extracted by force a recognition of his royal title from the Pope in 1139 (Treaty of Mignano). Lothair's successor Conrad III was approached in 1140 for a royal German bride for John's youngest son Manuel. Bertha of Sulzbach, Conrad's sister-in-law, was chosen and despatched to Byzantium. At much the same time Roger II applied to John II for an imperial bride for his son, but was unsuccessful.
John's penchant for interfering with his wife's family, the rulers of Hungary, was problematic. The welcome accorded to ousted claimants of the Hungarian throne in Constantinople was seen by the Byzantines as a useful insurance policy and source of political leverage. However, the Hungarians treated this interference as a fighting matter. A Hungarian alliance with the Serbs produced serious consequences for continued Byzantine dominance in the western Balkans.
In the East John attempted, like his father, to exploit the differences between the Seljuq Sultan of Iconium and the Danishmendid dynasty controlling the northeastern, inland, parts of Anatolia. In 1134 the Seljuq sultan Mas'ud provided troops for John's attack on the Danishmend-held city of Kastamuni, however, the alliance proved unreliable as the Seljuq troops abandoned the expedition, decamping during the night.
In the Crusader states of the Levant it was generally admitted that the Byzantine claims over Antioch were legally valid, though it was pragmatically viewed that only when the Byzantine emperor was in a position to enforce them militarily were they likely to be recognised in practice. The high point of John's diplomacy in the Levant was in 1137 when he extracted formal homage from the rulers of the Principality of Antioch, County of Edessa and the County of Tripoli. The Byzantine desire to be seen as holding a level of suzerainty over all of the Crusader states was taken seriously, as evidenced by the alarm shown in the Kingdom of Jerusalem when John informed King Fulk of his plan for an armed pilgrimage to the Holy City (1142).
The reign of John II was taken up with almost constant warfare and, unlike his father who delighted in active participation in theological and doctrinal disputes, John appears to have been content to leave ecclesiastical matters to the Patriarch and the church hierarchy. Only when religion impinged directly on imperial policy, as in relations with the papacy and the possible union of the Greek and Latin churches, did John take an active part. He organised a number of disputations between Greek and Latin theologians.
John, alongside his wife who shared in his religious and charitable works, is known to have undertaken church building on a considerable scale, including construction of the Monastery of Christ Pantokrator (Zeyrek Mosque) in Constantinople. This monastery, with its three churches, has been described as one of the most important and influential architectural constructions of Middle Byzantine Constantinople. Attached to the monastery was a hospital, of 5 wards, open to people of all social classes. The hospital was staffed by trained layman doctors rather than monks. The monastery also served as the imperial sepulchre for the Komnenian dynasty.
Very active persecution of the followers of the Paulician and Bogomil heresies characterised the last few years of the reign of Alexios I. No records from the reign of John mention such persecution, though countermeasures against heresy by the Byzantine Church remained in force. A permanent synod in Constantinople investigated the writings of a deceased monk named Constantine Chrysomallos which had been circulating in certain monasteries. These works were ordered to be burnt by the Patriarch of Constantinople, Leo Styppes, in May 1140, on the grounds that they incorporated elements of Bogomil belief and practices.
One of the few members of the imperial family to be placed in an important position by John was his cousin Adrian Komnenos (son of John's uncle the sebastokrator Isaac). Adrian had become a monk and had accompanied John on his campaigns of 1138. Soon afterwards Adrian was appointed Archbishop of Bulgaria. Bulgaria was an autocephalus see and required a prestigious man as archbishop.
Though he fought a number of notable pitched battles, the military strategy of John II relied on taking and holding fortified settlements in order to construct defensible frontiers. John personally conducted approximately twenty five sieges during his reign.
After his accession, John II had refused to confirm his father's 1082 treaty with the Republic of Venice, which had given the Italian republic unique and generous trading rights within the Byzantine Empire. Yet the change in policy was not motivated by financial concerns. An incident involving the abuse of a member of the imperial family by Venetians led to a dangerous conflict, especially as Byzantium had depended on Venice for its naval strength. After a Byzantine retaliatory attack on Kerkyra, John exiled the Venetian merchants from Constantinople. But this produced further retaliation, and a Venetian fleet of 72 ships plundered Rhodes, Chios, Samos, Lesbos, Andros and captured Kefalonia in the Ionian Sea. Eventually John was forced to come to terms; the war was costing him more than it was worth, and he was not prepared to transfer funds from the imperial land forces to the navy for the construction of new ships. John re-confirmed the treaty of 1082. Nevertheless, this embarrassment was not entirely forgotten, and it seems likely that it played a part in inspiring John's successor (Manuel I Komnenos) to re-establish a powerful Byzantine fleet some years later.
In 1119–1121 John defeated the Seljuq Turks, establishing his control over southwestern Anatolia. However, immediately afterwards, in 1122, John quickly transferred his troops to Europe to counter a Pecheneg invasion across the Danube frontier into Paristrion. These invaders had been auxiliaries of the Prince of Kiev. John surrounded the Pechenegs as they burst into Thrace, tricked them into believing that he would grant them a favourable treaty, and then launched a devastating surprise attack upon their fortified camp. The ensuing Battle of Beroia was hard fought, John was wounded in the leg by an arrow, but by the end of the day the Byzantine army had won a crushing victory. The decisive moment of the battle was when John led the Varangian Guard, largely composed of Englishmen, to assault defensive Pecheneg wagon laager, employing their famous axes to hack their way in. The battle put an effective end to the Pechenegs as an independent people; many of the captives taken in the conflict were settled as soldier-farmers within the Byzantine frontier.
John's marriage to the Hungarian princess Piroska involved him in the dynastic struggles of the Kingdom of Hungary. In giving asylum to Almos, a blinded claimant to the Hungarian throne, John aroused the suspicion of the Hungarians. The Hungarians, led by Stephen II, then invaded Byzantium's Balkan provinces in 1127, with hostilities lasting until 1129; however, an alternative chronology has been suggested with the Hungarian attack and Byzantine retaliation taking place in 1125 with a renewal of hostilities in 1126. John launched a punitive raid against the Serbs, who had dangerously aligned themselves with Hungary, many of whom were rounded up and transported to Nicomedia in Asia Minor to serve as military colonists. This was done partly to cow the Serbs into submission (Serbia was, at least nominally, a Byzantine protectorate), and partly to strengthen the Byzantine frontier in the east against the Turks. The Serbs were forced to acknowledge Byzantine suzerainty once again. The Serbian campaign may have taken place between two distinct phases in the war against Hungary. The Hungarians attacked Belgrade, Nish and Sofia; John, who was near Philippopolis in Thrace, counterattacked, supported by a naval flotilla operating on the Danube. After a challenging campaign, the details of which are obscure, the emperor managed to defeat the Hungarians and their Serbian allies at the fortress of Haram or Chramon, which is the modern Nova Palanka; many Hungarian troops were killed when a bridge they were crossing collapsed as they were fleeing from a Byzantine attack. Following this the Hungarians renewed hostilities by attacking Branicevo, which was immediately rebuilt by John. Further Byzantine military successes, Choniates mentions several engagements, resulted in a restoration of peace. The Byzantines were confirmed in their control of Branicevo, Belgrade and Zemun and they also recovered the region of Sirmium (called Frangochorion in Choniates), which had been Hungarian since the 1060s. The Hungarian pretender Almos died in 1129, removing the major source of friction.
Early in John's reign the Turks were pressing forward against the Byzantine frontier in western Asia Minor, and he was determined to drive them back. In 1119, the Seljuqs had cut the land route to the city of Attaleia on the southern coast of Anatolia. John II and Axouch the Grand Domestic recaptured Laodicea and Sozopolis, re-opening land communication with Attaleia. This route was especially important as it also led to Cilicia and the Crusader states of Syria.
Following the end of hostilities with Hungary, John was able to concentrate on Asia Minor during most of his remaining years. He undertook a campaign against the Danishmendid emirate in Malatya on the upper Euphrates from 1130 to 1135. Thanks to his energetic campaigning, Turkish attempts at expansion in Asia Minor were halted, and John prepared to take the fight to the enemy. In order to restore the region to Byzantine control, he led a series of well planned and executed campaigns against the Turks, one of which resulted in the reconquest of the ancestral home of the Komnenoi at Kastamonu (Kastra Komnenon); he then left a garrison of 2,000 men at Gangra. John quickly earned a formidable reputation as a wall-breaker, taking one stronghold after another from his enemies. Regions that had been lost to the empire since the Battle of Manzikert were recovered and garrisoned. Yet resistance, particularly from the Danishmends of the northeast, was strong, and the difficult nature of holding the new conquests is illustrated by the fact that Kastamonu was recaptured by the Turks even as John was in Constantinople celebrating its return to Byzantine rule. John persevered, however, and Kastamonu soon changed hands once more.
In the spring of 1139, the emperor campaigned with success against Turks, probably nomadic Turkomans, who were raiding the regions along the Sangarios River, striking their means of subsistence by driving off their herds. He then marched for the final time against the Danishmend Turks, his army proceeding along the southern coast of the Black Sea through Bithynia and Paphlagonia. The breakaway Byzantine regime of Constantine Gabras in Trebizond was ended, and the region of Chaldia brought back under direct imperial control. John then besieged but failed to take the city of Neocaesarea, in 1140. The Byzantines were defeated by the conditions rather than by the Turks: the weather was very bad, large numbers of the army's horses died, and provisions became scarce.
In the Levant, the emperor sought to re-inforce Byzantine claims to suzerainty over the Crusader States and to assert his rights over Antioch. In 1137 he conquered Tarsus, Adana, and Mopsuestia from the Principality of Armenian Cilicia, and in 1138 Prince Levon I of Armenia and most of his family were brought as captives to Constantinople. This opened the route to the Principality of Antioch, where Raymond of Poitiers, Prince of Antioch, and Joscelin II, Count of Edessa, recognized themselves as vassals of the emperor in 1137. Even Raymond II, the Count of Tripoli, hastened northwards to pay homage to John, repeating the homage that his predecessor had given John's father in 1109. There then followed a joint campaign as John led the armies of Byzantium, Antioch, and Edessa against Muslim Syria. Aleppo proved too strong to attack, but the fortresses of Balat, Biza'a, Athereb, Maarat al-Numan, and Kafartab were taken by assault.
Although John fought hard for the Christian cause in the campaign in Syria, his allies Prince Raymond of Antioch and Count Joscelin II of Edessa sat around playing dice instead of helping John to press the Siege of Shaizar. The Crusader Princes were suspicious of each other and of John, and neither wanted the other to gain from participating in the campaign. Raymond also wanted to hold on to Antioch, which he had agreed to hand over to John if the campaign was successful in capturing Aleppo, Shaizar, Homs, and Hama. Latin and Muslim sources describe John's energy and personal courage in prosecuting the siege. The city was taken, but the citadel defied assault. The Emir of Shaizar offered to pay a large indemnity, become John's vassal, and pay yearly tribute. John had lost all confidence in his allies, and a Muslim army under Zengi was approaching to try to relieve the city, therefore the emperor reluctantly accepted the offer. The emperor was distracted by a Seljuq raid on Cilicia and developments in the west, where he was pursuing a German alliance directed against the threat posed by the Normans of Sicily. Joscelin and Raymond conspired to delay the promised handover of Antioch's citadel to the emperor, stirring up popular unrest in the city directed at John and the local Greek community. John had little choice but to leave Syria with his ambitions only partially realised.
In early 1142 John campaigned against the Seljuqs of Iconium to secure his lines of communication through Antalya. During this campaign his eldest son and co-emperor Alexios died of a fever. Having secured his route, John embarked on a new expedition into Syria determined to reduce Antioch to direct imperial rule. This expedition included a planned pilgrimage to Jerusalem on which he intended to take his army. King Fulk of Jerusalem, fearing that the emperor's presence with overwhelming military force would constrain him to make an act of homage and formally recognise Byzantine suzerainty over his kingdom, begged the emperor to bring only a modest escort. Fulk cited the inability of his largely barren kingdom to support the passage of a substantial army. This lukewarm response resulted in John II deciding to postpone his pilgrimage. John descended rapidly on northern Syria, forcing Joscelin II of Edessa to render hostages, including his daughter, as a guarantee of his good behaviour. He then advanced on Antioch demanding that the city and its citadel be surrendered to him. Raymond of Poitiers played for time, putting the proposal to the vote of the Antiochene general assembly. With the season well advanced John decided to take his army into winter quarters in Cilicia, proposing to renew his attack on Antioch the following year.
Having prepared his army for a renewed attack on Antioch, John amused himself by hunting wild boar on Mount Taurus in Cilicia, where, on April 8, 1143, he accidentally cut himself on the hand with a poisoned arrow. John initially ignored the wound and it became infected, he died a number of days after the accident, probably of septicaemia. It has been suggested that John was assassinated by a conspiracy within the units of his army of Latin origins who were unhappy at fighting their co-religionists of Antioch, and who wanted to place his pro-western son Manuel on the throne. However, there is very little overt support for this hypothesis in the primary sources. John's final action as emperor was to choose Manuel, the younger of his surviving sons, to be his successor. John is recorded as citing two main reasons for choosing Manuel over his older brother Isaac: Isaac's irascibility, and the courage that Manuel had shown on campaign at Neocaesareia. Another theory alleges that the reason for this choice was the AIMA prophecy, which foretold that John's successor should be one whose name began with an "M". Fittingly, John's close friend John Axouch, although he is recorded as having tried hard to persuade the dying emperor that Isaac was the better candidate to succeed, was instrumental in ensuring that Manuel's assumption of power was free from any overt opposition.
Historian John Birkenmeier has recently argued that John's reign was the most successful of the Komnenian period. In The Development of the Komnenian Army 1081–1180, he stresses the wisdom of John's approach to warfare, which focused on sieges rather than risking pitched battles. Birkenmeier argues that John's strategy of launching annual campaigns with limited, realistic objectives was a more sensible one than that followed by his son Manuel I. According to this view, John's campaigns benefited the Byzantine Empire because they protected the empire's heartland, which lacked reliable borders, while gradually extending its territory in Asia Minor. The Turks were forced onto the defensive, while John kept his diplomatic situation relatively simple by allying with the Holy Roman Emperor against the Normans of Sicily.
Overall, it is clear that John II Komnenos left the empire a great deal better off than he had found it. By the time of his death substantial territories had been recovered, and the goals of the recovery of control over central Anatolia and the re-establishment of a frontier on the Euphrates seemed achievable. However, the Greeks of the interior of Anatolia were becoming increasingly accustomed to Turkish rule and often found it preferable to that of Byzantium. Also, though it was relatively easy to extract submission and admissions of vassalage from the Anatolian Turks, Serbs and Crusader States of the Levant, converting these relationships into concrete gains for the security of the Empire had proven elusive. These problems were left for his gifted and mercurial son, Manuel, to attempt to solve.
John II Komnenos married Princess Piroska of Hungary (renamed Irene), a daughter of King Ladislaus I of Hungary in 1104; the marriage was intended as compensation for the loss of some territories to King Coloman of Hungary. She played little part in government, devoting herself to piety and their large brood of children. Irene died on August 13, 1134 and was later venerated as Saint Irene. John II and Irene had 8 children:
- Alexios Komnenos, co-emperor from 1122 to 1142
- Maria Komnene (twin to Alexios), who married John Roger Dalassenos
- Andronikos Komnenos (died 1142)
- Anna Komnene, who married Stephen Kontostephanos
- Isaac Komnenos (died 1154)
- Theodora Komnene, who married Manuel Anemas
- Eudokia Komnene, who married Theodore Vatatzes
- Manuel I Komnenos (died 1180)