The Commonwealth of the Philippines (Tagalog: Komonwelt ng Pilipinas) was the administrative body that governed the Philippines from 1935 to the beginning of Japanese occupation and eventual annexation following the Pacific War. It replaced the Insular Government, a United States territorial government, and was established by the Tydings–McDuffie Act. The Commonwealth was designed as a transitional administration in preparation for the country's full achievement of independence. During its more than a decade of existence, the Commonwealth had a strong executive and a Supreme Court. Its legislature, dominated by the Nacionalista Party, was at first unicameral, but later bicameral. In 1937, the government selected Tagalog–the language of Manila and its surrounding provinces–as the basis of t