Haiphong, the capital of Vietnam's Haiphong Province, is the third largest city in the country. It is situated along the banks of the Cam River, an important waterway that has transported goods to the north for many centuries. Haiphong remained a small port city until 1874 when it was ceded to France. By the end of the 19th century, the French had expanded the harbour, competing with Hong Kong's trade. In 1946 tensions between France and Vietnam grew due a series of conflicts, and the French began bombing Haiphong, killing thousands of civilian Vietnamese and marking the beginning of the First Indochinese War.