The modern Korean Army traces its lineage back to the Gwangmu Reform, when the Beolgyegoon was established by Emperor Gojong in 1881. Under a restructuring plan aimed at reducing redundancy, the Second ROK Army was converted as the Second Operational Command on October 31, 2007, and the First and Third ROK Armies will be merged as the First Operations Command in 2014. The First Army was responsible for the defense of the eastern section of the DMZ whereas the 2nd OC formed the rearguard. The Third Army was responsible for the defense of the capital as well as the western section of the DMZ. Each with its own headquarters, corps, and divisions. The ROK Army was formerly organized into 3 armies: the First Army (FROKA), Third Army (TROKA) and Second Operational Command. The current administration has initiated a program over the next two decades to design a purely domestic means of self-defense, whereby South Korea would be able to fully counter a North Korean attack. The army is structured to operate in both the mountainous terrain native to the Korean Peninsula (70% mountainous) and in North Korea with its 1 million strong Korean People's Army, two-thirds of which is permanently garrisoned in the frontline near the DMZ. 4 Equipment of the Republic of Korea Army.3.4 Third Republic of Korea Army (TROKA) (3야전군).3.2 First Republic of Korea Army (FROKA) (1야전군).3.1 Republic of Korea Army Headquarters (대한민국 육군본부).