 Valenzuela, then a municipality, was separated from Bulacan to form the Metropolitan Manila Area on November 7, 1975 by virtue of Presidential Decree No.824.Afterwards, the reduced province of Bulacan was represented in the Interim Batasang Pambansa as part of Region III from 1978 to 1984, and returned four representatives, elected at large, to the Regular Batasang Pambansa in 1984.