Byzantine Commonwealth is a term coined by 20th century historians to refer to the area where Byzantine liturgical tradition was spread during the Middle Ages by Byzantine missionaries. This area covers approximately the modern-day countries of Bulgaria, the Republic of Macedonia, Montenegro, Russia, Serbia, Romania, Ukraine, Georgia, Moldova and Belarus. The most important treatment of the concept is a study by Dimitri Obolensky, The Byzantine Commonwealth (1971).
- Obolensky, Dimitri. The Byzantine Commonwealth: Eastern Europe, 500-1453. New York, NY: Praeger Publishers Inc., 1971. ISBN 978-1597407359 (hardcover; ACLS Humanities E-Book (May 1, 2009)) (Available as an ebook download, here)
- Meyendorff, John. The Byzantine Legacy in the Orthodox Church. St Vladimir's Seminary Press, 1982. ISBN 0913836907.