1. Introduction

John II Komnenos was born in the porphyra Chamber of the Great Palace of Constantinople in 1087 to Emperor Alexios I Komnenos and Eirene Doukaina, giving him his frequently used title of porphyrogennetos: ‘purple-born’ (for John II, see: ^[1]). Alexios had come to power in 1081 after a decade of civil wars and invasions following the defeat of Emperor Romanos IV Diogenes to the Seljuk Turks at the battle of Manzikert, and the loss of Bari, last Byzantine outpost in Italy, to the Normans. Alexios’ mother, Anna Dalassene, arranged the marriage between Alexios and Eirene Doukaina—from the rival Doukas family—in order to forge a dominant coalition of leading families in Byzantium, and originally this had also seen Alexios’ eldest child, Anna Komnene, betrothed to Constantine Doukas. However, with the birth of John and Constantine’s death, Alexios could crown John as a new heir to the Komnenoi, though in rhetorical works John is also referred to as a Komnenos-Doukas. John’s sister, Anna, wrote the famous Alexiad chronicling Alexios’ reign, in which she describes the young John as having dark skin and eyes, and though our images of him do not show this, he is occasionally given the nickname of ‘Black-John’ in other sources, including by the crusader historian William of Tyre. He is also frequently referred to as Kaloioannes, ‘Good-John’, in both Greek and non-Greek texts, such was his positive reputation among contemporaries and those that followed him.

As a child, John was given as a hostage to the warriors of the First Crusade outside Constantinople in 1097, to stand surety for his father’s good behavior. In 1105, he married Piroska-Eirene Árpád, daughter of King Ladislaus I of Hungary and Adelaide of Rheinfelden, as part of Alexios’ plan to bring Hungary into an alliance with Byzantium against the Normans who had invaded the Balkans.

At Alexios’ death in 1118, John saw off a challenge to his succession from his mother Eirene, sister Anna and her husband Nikephoros Bryennios, though the seriousness of that challenge has been debated by historians. To solidify his rule, John led opening campaigns in southwestern Anatolia, and by conquering Laodikeia and Sozopolis, he reopened the land route to Attaleia and brought all of western Anatolia under his aegis, allowing him to crown his own eldest son, Alexios, as co-emperor in 1119. John spent the 1120s mainly in the Balkans, first seeing off a major invasion of Pechenegs and Cumans, which he defeated at the battle of Beroea in 1122, and then dealing with an insurrection by the anti-Byzantine Serb prince Juraj of Raška against the pro-Byzantine King Gradinja, before having to see off a Hungarian invasion led by King Stephen II Árpád. These troubles allowed Doux Constantine Gabras of Trebizond to rebel in 1126, and they forced John to concede trading privileges to Venice in the same year; these they had enjoyed under Alexios, but John had not renewed them in 1118, leading to frequent Venetian raids on Byzantine islands from 1122 onwards.

Though John had settled his western provinces by 1130, there was then an attempted coup by his brother, Sebastokrator Isaac Komnenos. Isaac and his son fled the capital but then sought to forge a coalition against John amongst his rivals in Anatolia, drawing John back into wars there. Over the course of several campaigns, John subjugated the north central Anatolian region of Paphlagonia, for which he celebrated a Roman Triumph in classical style in Constantinople in 1133. In response to an attack on Seleukeia by Prince Leo of Armenian Cilicia, an erstwhile ally of Isaac’s, John invaded Cilicia in 1137 and captured the entire region in a lightning campaign that brought him to the gates of Antioch. Here, he sought to enforce the treaty of Devol whereby the rulers of Antioch were bound to hand over the city to him. By way of negotiation, John and the crusaders campaigned together in Syria against the Muslims, but they were unable to take Aleppo or Shaizar, partially due to the reluctance of the crusaders to fully support John. The emperor was then forced from Antioch by anti-Greek riots that followed his demand that the citadel of Antioch be handed over to him, and then he was recalled to the west by news of renewed Turkish aggression. John spent the years 1139–1142 campaigning once more in Anatolia, where he succeeded in putting down the rebellious Gabras of Trebizond, but he failed to take the city of Neakaisareia from the Turks. In 1142, he returned east to enforce his demands on Antioch, and he made his intentions clear that he planned to travel to Jerusalem as well. Before his designs could be acted upon, John cut his hand whilst hunting in Cilicia; the wound grew infected, and he was obliged to accede to his youngest son Manuel becoming his heir before he died in 1143.

John is otherwise known for co-founding with his wife an immense philanthropic institution associated with a monastery dedicated to Christ Pantokrator (‘ruler of all’). His best-known iconographic representation is a mosaic of him, his wife, the Theotokos and Christ in the Great Church of Hagia Sophia. Whilst there is also an image of him in a contemporary ornate gospel book, his most common representations are found on his many coin issues and seals (for a general bibliography on Byzantine iconography, see: ^[2]).