Emigrated during the Civil War. Lived in Prague. In the early 1920s was close to the Eurasian movement, distancing himself from it later. Professor of patrology at the Paris Theological Institute, 1926-1939.
Gained a worldwide reputation as a scholar of patristics. Professor, later Dean of the St. Vladimir Theological seminary in New York, 1939-1955. Professor of Harvard and Princeton Universities.
Active participant in the oecumenical movement, where he represented the orthodox tradition. Widely respected for his scholarship and erudition.