Saint Gury Rugotin, the first archbishop of Kazan, came from the nobility of the former city of Radonezh, and was known to the world as Gregory. At a young age, Grigory joined the service of Prince Ivan Penkov. The prince was so pleased with him that he entrusted him with the management of the entire house. But this power of attorney did not last long. Other servants of the prince, out of envy for Gregory, slandered him that he was in a criminal relationship with the princess. Annoyed by the false accusation, the prince ordered Gregory to be imprisoned in a dungeon deliberately set up in a deep pit. The innocent sufferer languished there for two years, because two years later the prisoner's door opened freely. Recognizing his salvation as the providence of God, he renounced the world and went to the monastery of St. Joseph of Volokolamsk. There he donned monastic robes, taking the name Gury, and soon (1522) was appointed abbot of the monastery; then he was transferred to the Selizharov monastery, and on February 3, 1555, he was ordained archbishop of the new Kazan diocese.

Gury founded two monasteries there for the education of Christian and pagan children; in addition, under his special supervision, a stone cathedral was built in the name of the Annunciation of the Blessed Virgin Mary. Taking care of his flock, Saint Gury multiplied it, converting many Muslims to the Christian faith. He died on December 4, 1563, having accepted the schema two days before his death.

In 1630, the relics of Saint Gury, found on October 4, 1595, were transferred from the Saviour's Transfiguration Monastery to the Church of the Annunciation in Kazan. Since 1918, they have been located in the Kazan Bogoroditsky Monastery, then in the parish church of Paraskeva Friday, in the Peter and Paul Cathedral, and since the mid-1930s they have been moved to the church of the Holy Princes Theodore, David and Constantine, the Wonderworkers of Yaroslavl, at the Arsky cemetery, where they are currently wanted.

Gury founded the Kazan Diocese. In 1555, by decree of Tsar John Vasilyevich, Metropolitan Macarius established the Kazan Archdiocese of the third degree. After the archbishops, there have been metropolitans since 1589, and bishops and archbishops since 1832. At first, the diocesan bishops were called Kazan and Astrakhan, then, from 1602, Kazan and Sviyazhsk, and from 1799 Kazan and Simbirsk. In 1799, the Kazan Vicar Diocese was established, the bishops of which were ordered to write Sviyazhsk, but in 1802 the Kazan vicariates were abolished.