qnli question: In what year did the Korean War begin? sentence: The Korean War (in South Korean Hangul: 한국전쟁, Hanja: 韓國戰爭, Hanguk Jeonjaeng, "Korean War"; in North Korean Chosungul: 조국해방전쟁, Joguk Haebang Jeonjaeng, "Fatherland Liberation War"; 25 June 1950 – 27 July 1953)[a] was started when North Korea invaded South Korea.