East City is a city in the eastern region of Amestris, which serves as the military command base for the area. For most of the series' first arc, East City is where Colonel Roy Mustang and his subordinates are stationed as well as the point where Edward Elric must make his official reports.
Though considered by many as a "backwater" place with little future, East City boasts what is recognized as Amestris' strongest offensive force. Having the closest proximity to Ishval, the Eastern Military bore the greatest burden during the Ishvalan Civil War, leaving it with many veteran soldiers. Much like the northern Briggs' soldiers share a special bond with their leader, East forces hold Lieutenant General Grumman in very high regards, going as far as betraying Central Command and King Bradley on his orders.