Gyeongui Line (1904–1945)
Following Japan's defeat in the Pacific War and the subsequent partition of Korea, the Gyeongui Line was divided at the 38th parallel between North and South Korea. On 25 August 1945, the Soviet Army began operating trains on the line north of Sariwon, whilst trains in the south terminated at Gaeseong. In 1946, the railways in both North and South were nationalised, creating the Korean National Railroad in the South and the Korean State Railway in the North. After the Korean War, the Gyeongui Line was split into three sections. In the South, the Seoul–Jangdan section became the KNR's Gyeongui Line, retaining the same name; in the North, the Bongdong–Pyeongyang section became the P'yŏngbu Line, whilst the Pyeongyang–Sinuiju section became the P'yŏngŭi Line.
North Korea–South Korea relations
North Korea invaded the South on June 25, 1950, and swiftly overran most of the country. In September 1950 the United Nations force, led by the United States, intervened to defend the South, and advanced into North Korea. As they neared the border with China, Chinese forces intervened on behalf of North Korea, shifting the balance of the war again. Fighting ended on July 27, 1953, with an armistice that approximately restored the original boundaries between North and South Korea. Syngman Rhee refused to sign the armistice, but reluctantly agreed to abide by it. The armistice inaugurated an official ceasefire but did not lead to a peace treaty. It established the Korean Demilitarized Zone (DMZ), a buffer zone between the two sides, that intersected the 38th parallel but did not follow it. North Korea has announced that it will no longer abide by the armistice at least six times, in the years 1994, 1996, 2003, 2006, 2009, and 2013.