Superior of Optina
From 1862 to 1894 Isaac served as Superior of the Optina Hermitage, near Kozelsk. During this period Optina was regarded as the most important spiritual center of the Church of Russia in the nineteenth century, renowned for the renewal of monastic life in the hesychastic tradition. He held the rank of schema-archimandrite.
His monastic life was influenced by the Optina elder Ambrose, one of the best-known of the Optina spiritual fathers. As superior, Isaac belonged to the unbroken line of elders through whom the monastery exercised its wider influence on Russian spiritual life.