Byzantine Armenia

Byzantine Armenia, sometimes known as Western Armenia, is the name given to parts of the Kingdom of Armenia that became part of the Byzantine Empire (eastern Roman Empire). The size of the area changed multiple times through the course of history.
The Byzantine and Sassanid Empires divided Armenia in 387 and 428 AD. Western Armenia was part of Byzantine rule, whilst Eastern Armenia (Persianized Armenia) was part of the Sassanids. Even after the Bagratid Armenian Kingdom was created, parts of historic Armenia and Armenian-inhabited areas were still under Byzantine rule.