In 1858 Constantius, the Metropolitan of Trebizond in Asia Minor, approached Alexander II requesting permission to collect money in Russia for the construction of an Orthodox cathedral in his city. The Emperor gave his consent and in response the Metropolitan presented him with a magnificent parchment Gospel. The gift from Trebizond was added to the still small, but already high-quality collection of Greek manuscripts in the Imperial Public Library. In his annual report written to the Minister of the Imperial Court the director stated that "the Greek Gospel donated by the Emperor and presented to His Majesty by the Metropolitan of Trebizond ... is the chief and most important of all the acquisitions which the library made in 1858." The brief description included in the report indicates that "the manuscript consists of two parts: a) the actual Gospel... in an eleventh-century cursive hand ... and b) 14 sheets far older than the Gospel itself, which were sewn in after it had already been bound". In his catalogue of the Greek manuscripts published in 1864 the curator of the library's theological manuscripts, Eduard von Muralt,
identified the subjects of the miniatures painted on these older pages and gave a detailed palaeographical description and linguistic analysis of the text of the Trebizond fragments. By that time, they had already been removed from the eleventh-century Gospel. It is this manuscript which has subsequently been referred to as the Gospel of Trebizond.
In 1902 the Public Library acquired one further folio of the Gospel of Trebizond. The annual report stated " it bears the text of the Gospel reading for the feast of Our Lord's Baptism and is decorated with a miniature depicting that event."
Some time later Professor Fiodor Uspensky, the director of the Russian Archaelogical Institute in Constantinople, put forward the theory that the Gospel of Trebizond in the St Petersburg Public Library is a fragment of the book mentioned in a fourteenth-century manuscript from Trebizond - the Tale of the Miracles of the Holy Gospel. The fourteenth-century source says that, during a war with Sultan Ala ad-Din of Kenya, Emperor Andronicus Hidus of Trebizond prayed before the patron icon of the city, the Virgin with the Golden Head, for help. After gaming victory, he decorated this icon with precious stones and pearls received from the defeated Sultan, and also presented the Virgin with "a Gospel codex of selected readings, superbly decorated with many golden images". Judging by the abundance of gold and the great artistry of the miniature-painters, the Gospel of Trebizond could indeed have been commissioned by members of the imperial family. It may have been kept in the library of the Comneni family in Constantinople and then, after the city's fall to Western Crusaders in 1204, have passed to the Trebizond branch of the Comneni. The magnificent painting in the Gospel, together with its ortho-graphically flawless text, places it among the finest examples of Byzantine art to have survived from the tenth century.