The Gyeongbu Line (Gyeongbuseon) is a railway line in South Korea and is considered to be the most important and one of the oldest ones in the country. It was constructed in 1905, connecting Seoul with Busan via Suwon, Daejeon, and Daegu. It is by far the most heavily travelled rail line in South Korea.
All types of high-speed, express, local, and freight trains provide frequent service along its entire length.
In 1894–1895, the Empire of Japan and Qing China fought the First Sino-Japanese War for influence over Korea. Following the war, Japan competed with the Russian Empire's railway expansion in Northeast Asia, which led it to seek the right from the Korean Empire to build a railway from Busan to Keijō. This railway line was intended by Japan to solidify its strategic positions against Russia, which it would later go to war. Surveying began in 1896, and in spite of local protests, the Korean Empire gave Japan the right to build the line in 1898. Construction of the railway started on August 20, 1901, with a ceremony at Eitōho-ku, Keijō. Construction was supervised by Japanese, with local Koreans commandeered into forced labor and paid with coupons.
Japan also sought to gain control of the Keigi Railway project that was to continue tracks further north, recognizing the trunk route as a means to keep Korea under its influence. After the outbreak of the Russo-Japanese War, Japan ignored Korea's declaration of neutrality and transported troops to Incheon. Japan also forced the Korean government to sign an agreement that ceded its control of the railway. Japanese military bases were established in connection with the railway, the biggest of them next to Ryūzan Station in Keijō.
The Gyeongbu Line was publicly inaugurated on January 1, 1905 as the Keibu Railway. The first trains travelled the line in 17 hours 4 minutes. By April 1906, travel time was reduced to 11 hours, while top speed was . The line developed into the backbone of transport in Korea under Japanese rule.