Abbot of the Pskov Caves
When Cornelius arrived, the Pskov Caves Monastery was in poor condition; under his direction it reached its prime. Made abbot in 1529 at the age of twenty-eight, he led the community for over forty years, during which the brethren grew from 15 to 200 men.
He undertook an extensive program of building. He raised a church of the Annunciation of the Most Holy Theotokos in 1541 and a church of the Protection of the Most Holy Theotokos in 1559, enlarged the monastery's cave structures, and built a massive stone wall around the monastery between 1558 and 1565, crowned with a stone church dedicated to Saint Nicholas over the gates.