Prior to gaining joint representation, Las Piñas and Parañaque were represented under the provinces of Manila (1898–1899) and Rizal (1907–1972).
Parañaque was annexed to the City of Greater Manila and was represented as part of Manila's at-large district during the National Assembly of the Japanese-sponsored Second Philippine Republic from 1943 to 1944, while Las Piñas remained under Rizal.
These two municipalities were separated from the province to form the Metropolitan Manila Area on 7 November 1975 by virtue of Presidential Decree No.
824;[1] Metro Manila was represented in the Interim Batasang Pambansa as Region IV from 1978 to 1984.
The combined representation of the two municipalities lasted until the abolition of the Regular Batasang Pambansa in the aftermath of the People Power Revolution in 1986.