Venerable Cyril the Abbot of White Lake

Cyril, born Kozma in 1337, served as treasurer to the Moscow boyar Timothy Velyaminov until Stephen of Makhra persuaded his master to let him become a monk. He took vows at the Simonov monastery in Moscow, knew Sergius of Radonezh, and in 1388 became its archimandrite, but soon gave up the office to live in his cell.

His Life tells that one night he heard the voice of the Mother of God sending him to Beloozero. In 1397 he set out with the monk Ferapont and on the shore of Lake Siverskoye dug himself a cave cell; from it grew the Kirillo-Belozersky monastery, one of the largest in the Russian north. He wrote letters of counsel to the princes of Moscow and died in 1427.