Activated in 1949, the regiment trained for more than a year before the outbreak of the war on June 25, 1950. On that day, half of the regiment led North Korean forces against South Korean troops by land and sea, pushing them back after several days of fighting. Over the next six weeks, the regiment advanced slowly down the Korean Peninsula, acting as a forward unit of the North Korean army. Suffering from a lack of supplies and mounting casualties, the regiment was committed to the Battle of Pusan Perimeter as part of a push to force United Nations (UN) troops out of Korea.