Following the Marco Polo Bridge Incident in July 1937, the Battle of Shanghai broke out between the Nationalist army of China and Imperial Japan. It became the catalyst and one of the bloodiest battles of the Second Sino-Japanese War, which continued until Japan's defeat in 1945 to end World War II. After conquering Shanghai in 1937, the Japanese installed a puppet government known as the Dadao Municipal Government of Shanghai, proclaimed in Pudong on 5 December 1937 to administer Japanese-occupied Shanghai in the early stages of the Second Sino-Japanese War.