The Chinese Republic was established in 1912 but, by 1931, had descended into a civil war, which the Japanese were quick to exploit. After several acts of aggression, beginning with the taking of Peking (now Beijing) and Tientsin, war was declared in July 1937. From the start, Japan had aerial superiority, but struggled to convert this into aerial supremacy. The capture of Shanghai in October 1937, added to Tsingtao and Ryojun already in their hands, gave the Japanese a string of mainland naval bases from which to launch air raids and supply their armies. However, the Chinese, with just 230 airworthy fighter planes to Japan’s 600 at the opening of hostilities, fought doggedly, winning many aerial engagements. Japanese air raids were widely distributed, but with a focus on Chungking, Hang-chou, Chang-Chou and Lan-Chou. The raids hit civilian targets, including hospitals, indiscriminately, and made frequent use of incendiaries.