The term ethnic diocese in relation to the structure of the Orthodox Church in the Western Hemisphere comes from the concept envisioned by Archbishop Tikhon to accommodated the administration in the Russian North American diocese of diverse cultural groups among the immigration in North America of Orthodox Christians during the early twentieth century.
As Orthodox immigrants arrived in North America around the turn of the nineteenth and twentieth centuries, the people general settled into communities that consisted of people of similar Old World national and/or cultural identities. While some early late nineteenth century, parishes began as multi-cultural parishes most of these divided along cultural and language lines as the parish community grew in size.
After Bishop Tikhon (Belavin) arrived to lead the Russian mission in 1897, he developed a course of action of grouping the parishes along cultural lines as exemplified when he consecrated Archimandrite Raphael (Hawaweeny) to lead the Syro/Arabic community.
St. Tikhon's approach of establishing a separate "diocese" for each cultural group differed from that used by the Roman Catholic Church of melding their cultural parishes into a common organization of dioceses.[]
The concept was also intended to consecrate bishops for other cultural groups including the Serbians, Albanians, Greeks, and others. As a result of the Bolshevik revolution in 1917, and the ecclesiastical disorganization that followed, the concept was not fulfilled. However, after the Metropolia, which formed from the Russian mission in North America after World War I, was granted autocephaly by the Church of Russia in 1970, a number of parishes in North America that broke from the administration of Mother Churches under Communist control were accepted as ethnic dioceses by the autocephalous Orthodox Church in America. These included Romanian, Bulgarian, and Albanian parishes.