[8] Although William Miller assumes that John was not old enough to assume the throne,[9] one primary source attests that more than one son was, indeed, old enough to do so: during the siege of Sinope, according to Ibn Bibi, when Kaykaus I told the city that unless they surrendered he would kill Alexios, who was his prisoner, the inhabitants replied that "he has grown sons in Trebizond who are capable of governing.

[13] In 1223 the Seljuk governor of Sinope sent ships to attack the coast of Trapezuntine Crimea (the so-called Perateia) in an effort to divert trade into his port.

A ship carrying the annual tribute of Perateia, with the archon of the province and a number of notables from Cherson on board, was driven by a storm into Sinope's harbour.

In violation of a treaty agreed to by the Turks and the Empire of Trebizond in 1220, the city's governor, Hetum, seized the vessel with its cargo, passengers, and crew and also sent a fleet to plunder Perateia.

The emperor inflicted considerable loss upon the advance guard of the sultan before withdrawing within the walls of the city, which were already accounted impregnable although they did not yet extend to the sea.

A string of attacks and counterattacks followed over the next few days (punctuated by a Seljuk embassy being shown the ample stores inside the city) ended with an attempt to storm the walls by night.

This last attack failed when a sudden thunderstorm, accompanied by torrential rain and hail, terrified and scattered the besiegers.

A pact was made between them that in the future the tie of vassalage, which had previously bound Trebizond to Iconium, should cease, and that the Trapezuntines should no longer be obliged either to perform military service to the sultan or to send tribute or gifts.

Melik is reported to have been so impressed by this moderation that he performed more than the treaty required by sending an annual present of Arab horses to Andronikos and money to the Monastery of St Eugenios.

In the first legend, the account of the siege compiled by John Lazaropoulos, who, under the name of Joseph, was Metropolitan of Trebizond in the second half of the fourteenth century, narrates the legend that a further ruse was perpetrated by the outraged St Eugenios, who appeared to Melik, the profaner of his shrine, in the guise of mayor of the city, who held its keys, and pretended to have been sent by the suffering citizens to invite him to enter.

In the second, Melik fled, only to fall into the hands of the mountaineers from Matzouka, and 150 years later a shrine erected to St Eugenios still marked the spot of his capture.

Iberia and Lazica, which had been subject to Trebizond, whose eastern frontier had been Soteropolis, separated themselves from the empire and formed an independent kingdom of Imereti under David VI Narin, son of the Georgian Queen Rusudan.