Ministry at the Trinity Monastery
Cyril was sent as hegumen, and later served as archimandrite, of the newly built Trinity Monastery in Astrakhan in 1568, in the period after the city was incorporated into the Muscovite state. The monastery he led stood at the frontier of an expanding Russian presence on the lower Volga, in a region with a substantial Muslim population.
During his leadership he oversaw the construction of churches at the monastery dedicated to the Most Holy Trinity, to the Entry of the Most Holy Mother of God into the Temple, and to Saint Nicholas. The sources remember him as devoted to the Christian enlightening of the Astrakhan region, and relate that by his meekness and piety he gained the respect even of the local Muslims, who called him 'Kara-Daud' — 'the Black David'.