Sergius of Radonezh
1314 — 1392
Born Bartholomew near Rostov, Sergius withdrew into the forests northeast of Moscow as a young man, built a small chapel to the Holy Trinity, and drew disciples who became the Trinity Lavra — still the foremost monastery in Russian Orthodoxy. He reformed Russian monasticism along communal lines and blessed Prince Dmitri Donskoi before the Battle of Kulikovo in 1380.