San Juan, formerly known as San Juan del Monte, was initially represented as part of the at-large district of the province of Manila in the Malolos Congress from 1898 to 1899. The then-town was later incorporated to the province of Rizal, established in 1901, and was represented as part of the first district of Rizal from 1907 to 1941 and from 1945 to 1972. When the then-town was merged to form the City of Greater Manila during World War II, it was represented as part of the at-large district of Manila from 1943 to 1944. San Juan was separated from Rizal on November 7, 1975 by virtue of Presidential Decree No. 824,[1] and was represented in the Interim Batasang Pambansa along with other Metropolitan Manila municipalities and cities as part of Region IV from 1978 to 1984.