 Prior to gaining joint representation, areas now under the respective jurisdictions of Malabon and Navotas were represented under Rizal (1907–1972), Region IV (1978–1984), and the parliamentary district of Malabon–Navotas–Valenzuela (1984–1986).Under the new Constitution which was proclaimed on 11 February 1987, the independent Metro Manila municipalities of Malabon and Navotas constituted a single congressional district, and elected its member to the restored House of Representatives starting that same year.The enactment of Republic Act No.