John II of Trebizond, born around 1262, ascended to the throne as Emperor of Trebizond in June 1280, following the betrayal and demise of his full-brother George. He was the youngest son of Emperor Manuel I and his third wife, Irene Syrikaina, a noblewoman from Trapezuntine lineage. John's reign marked a significant shift in the titles used by the rulers of Trebizond, transitioning from the traditional Byzantine title of 'Emperor and Autocrat of the Romans' to 'Emperor and Autocrat of all the East, the Iberians, and the Transmarine Provinces'. This change occurred despite the loss of Iberia during the reign of Andronikos I Gidos.
During his rule, John II faced numerous challenges that shaped his leadership and decisions. His marriage to the daughter of Byzantine Emperor Michael VIII Palaiologos was likely a strategic move to bolster his position and secure alliances. This period is notable as it provides a wealth of information about John's reign, thanks in part to the chronicle of Michael Panaretos, which, while often terse, offers a more detailed account of events during this time.
John II is the first ruler of Trebizond for whom a coherent narrative can be constructed, thanks to the combination of Panaretos' chronicles and additional external sources. His reign is characterized by a unique instance where both he and his eldest son, Alexios, appeared on the coins of Trebizond, suggesting John's intent to signal his choice of successor and solidify his legacy.