The Eastern Prelacy of the Armenian Apostolic Church is under the jurisdiction of the Holy See of the Great House of Cilicia, located in Antelias, Lebanon. The Prelacy office was established in New York City in 1958. The Prelacy has been responsible for a continuing program of community-wide activities: religious, educational, cultural, and social.
Having started with a relatively small number of affiliated churches, the Prelacy originally served the entire United States and Canada. As the number of churches grew and the membership increased, especially in California, the Prelacy jurisdiction was divided into two parts, the Eastern and Western Prelacies of the United States, including Canada as part of the Eastern Prelacy.
In 2002, a separate Prelacy of Canada was established. The actual area covered by the Eastern Prelacy extends from the Atlantic Coast to the Rocky Mountains. The demographic center of the Eastern Prelacy is in the northeast, where the Armenian population is most heavily concentrated in the United States megalopolis (New England to the District of Columbia).