Administration of the city was first formalized by King Chulalongkorn in 1906, with the establishment of Monthon Krung Thep Phra Maha Nakhon () as a national subdivision. In 1915, the ''monthon'' was split into several provinces, the administrative boundaries of which have since further changed. The city in its current form was created in 1972 with the formation of the Bangkok Metropolitan Administration (BMA), following the merger of Phra Nakhon Province on the eastern bank of the Chao Phraya and Thonburi Province on the west during the previous year.