This article examines the long and complex relationship between Japan and China, stretching back centuries. It explores why Japan wanted to gain control over various parts of Chinese territory, and looks at the political, economic and military factors that contributed to its desire for control. It also discusses the wars fought between the two countries, including the Sino-Japanese War (1894–1895) and Russo-Japanese War (1904–1905), as well as Japan's occupation of mainland China during World War II (1937–1945). Finally, it looks at how post-war relations have improved due to diplomatic efforts and economic aid provided by both sides.