After the outbreak of the Second Sino-Japanese War in 1937, the Kuomintang moved its seat of government from Nanjing to Chongqing. In 1939 the city was made a municipality under the Executive Yuan and in 1940 was made the provisional wartime capital of China. Chongqing endured years of intensive daytime and nighttime bombings by massed formations of Imperial Japanese Naval and Army Air Forces in the Battles of Chongqing and Chengdu; battles of which were fought entirely by opposing air forces and anti-aircraft defenses. In 1946, the seat of government was again moved, this time back to Nanjing. After the founding of the People's Republic of China in 1949, Chongqing remained the cultural and economic centre of southwestern China. In 1983, the economic reforms effected by Paramount Leader Deng Xiaoping were trialled in the city. In 1997 Chongqing became the one of four municipalities directly under the central government in China, and the only one in western China.