This lecture examines the pivotal Sino-Japanese War of 1894-1895, which profoundly influenced diplomatic relations in East Asia during the late 19th century. It delves into the background of the conflict, rooted in Japan's expansionist ambitions in Korea and the complex power dynamics between China, Korea, and Japan. The lecture highlights the escalating tensions leading up to the war, including the proxy struggles within Korea and the failed attempts at diplomatic resolutions. Additionally, it explores the conduct of the war, focusing on the decisive naval battle of the Yellow Sea and its ramifications for China's modernization efforts and diplomatic standing.