 Zambales, including the city of Olongapo (chartered in 1966), comprised a lone district until 1972.The province and chartered city were represented in the Interim Batasang Pambansa as part of Region III from 1978 to 1984.Zambales elected one representative to the Regular Batasang Pambansa in 1984, with Olongapo sending a separate representative as a highly urbanized city.