roka 0000 ROK Army



The Republic of Korea (R.O.K.-pronounced "rock") (Taehan Min'guk, or Hanguk, for short) was proclaimed on 15 August 1948 after U.N.-supervised elections, and the U.N. recognized the country on 15 December. Interestingly, South Korea was not admitted to the U.N. until 1991, the same year North Korea was accepted.

In 1945 the U.S. Military Government allowed the Office of the Director of National Defense to be established with authority over the Korean National Police and the new Bureau of the Armed Forces comprised of the Departments of the Army and Navy. The Office of the Director of National Defense was renamed the Department of Internal Security, and the Bureau of the Armed Forces became the Bureau of the Constabulary in June 1946. The Korean National Defense Constabulary (Choson Kyongbi-dae) began forming light infantry companies in the nation's eight provinces, and these were gradually expanded to provincial regiments in 1947. The regiments were soon redesignated the 1st-8th Constabulary Brigades. A 9th Brigade was later organized with the Constabulary growing to 50,000 men. Most of the Constabulary'S weapons were turned over from the U.S. Army occupation forces in June 1949. It had previously been armed with Japanese weapons. The R.O.K. Army (Tae-Hanna Min 'guk Yuk-Kun) was fanned on 15 August 1948 from the Korean Constabulary. Many of these troops had served in the Imperial Japanese Army, Chinese Nationalist-supported Korean Restoration Army (Kwangbok Kun), and the Chinese Liberation Army (communist) during World War II.

Between June 1948 and May 1949, the 1st, 2nd, 3rd, 5th, 6th, and 7th Infantry Divisions of the ROKA were organized from the 1st, 2nd, 9th, 5th, 4th, and 7th Constabulary Brigades, respectively. The 8th R.O.K. and Capital Divisions were organized in 1949. The Capital Division was actually an infantry division and later deployed as a frontline formation. Had it been assigned a number it would have been the l Oth Division. The Capital Security Command, responsible for the defense of Sŏul, was assigned the unnumbered Cavalry Regiment, a partly motorized unit with two dozen M8 and M20 armored cars and half that many M3 halftracks. In 1950 it was reorganized as a standard infantry regiment and reassigned to the 3rd RO.K. Division and later the Capital Division. The remaining 3rd, 6th, and 8th Constabulary Brigades were soon absorbed into the new divisions.

Other units were raised and by June 1950 with the ROKA consisted of 98,000 troops in eight divisions. Its authorized strength at the time was 65,000 men in the divisions and 35,000 in headquarters and service units. At the war's beginning the divisions were undermanned, severely short of equipment, and lacked some component units. The ROKA was especially deficient in artillery, antitank, antiaircraft, and armor capabilities. The degree of individual and leadership training was insufficient to the task at hand. Weapons, equipment, munitions, and supplies were totally inadequate to sustain high-tempo combat operations and to repel an invasion. Only the 1st, 2nd, 6th, and 7th RO.K. Divisions had three infantry regiments; the 5th had two regiments plus a separate battalion. Only five artillery battalions were organized, and these were assigned to the 1st, 2nd, 6th, 7th, and 8th RO.K. Divisions (a sixth was forming). There was also the 2,500-man separate 17th RO.K. Infantry Regiment, which was reassigned to the 2nd RO.K. Division in early 1951.

President Syngman Rhee was the commander-in-chief of the ROKA, while deputy commander-in-chief was Maj. Gen. Chae Byong Duk. The RO.K. Army Headquarters was located in Sŏul under Chief of Staff Maj. Gen. Chae Pyong. There were no intermediate corps headquarters at the time. The infantry units assigned to the R.O.K. divisions in June 1950 follow. Many of the regiments would be reassigned between divisions between 1950 and early 1951. The divisions' strengths are provided.

1st RO.K. Division (lIth, 12th, 13th Infantry Regiments) 9,715

2nd RO.K. Division (5th, 16th, 25th Infantry Regiments) 7,910

3rd RO.K. Division (22nd, 23rd Infantry Regiments) 7,059

5th RO.K. Division (15th, 20th Infantry Regiments, 1st Separate Infantry Battalion) 7,276

6th RO.K. Division (6th, 8th, 19th Infantry Regiments) 9,112

7th RO.K. Division (1st, 3rd, 9th Infantry Regiments) 9,698

8th R.O.K. Division (10th, 21st Infantry Regiments) 6,866

Capital RO.K. Division (2nd, 18th Infantry Regiments) 7,061


At the beginning of the Korean War (Hanguk Chonjaeng), these units were deployed from west to east along the 38th Parallel: the separate 17th Infantry Regiment, 1st, 7th, 6th, and 8th R.O.K. Divisions. The Capital Division was in Sŏul and the 2nd, 3rd, and 5th R.O.K. Divisions were scattered about the country conducting antiguerrilla operations and unit tactical training. Shortly after the North Korean invasion, the battered 2nd, 5th, and 7th R.O.K. Divisions were inactivated and their troops absorbed into the depleted 1st, 3rd, 6th, 8th, and

Capital RO.K. Divisions within the Pusan Perimeter. There remained only 54,000 troops of the preinvasion 98,000-man ROKA. The remnants of the 7th R.O.K. Division and the 500-man National Youth Group (NYG), an ROTC-like organization, continued to fight as the regimental-sized Task Force Min from late July to late August when it formed the core of the new 5th Infantry Regiment, 7th R.O.K. Division. I RO.K. Corps was activated at the beginning of July, soon followed by II RO.K. Corps. On 24 July 1950 the remaining ROKA divisions were reorganized as follows:

 I RO.K. Corps

Corps Troops

8th R.O.K. Division (10th, 16th, 21st Infantry Regiments)

Capital RO.K. Division (lst, 17th, 18th Infantry Regiments)

Task Force Min


II RO.K. Corps

 Corps Troops

1st R.O.K. Division (11th, 12th, 15th Infantry Regiments)

6th R.O.K. Division (2nd, 7th, 19th Infantry Regiments)


ROKA Troops and Reserve

ROKA Service Troops

3rd R.O.K. Division (Cavalry, 22nd, 23rd Infantry Regiments)

1,754 8,864 6,644 1,249 976 7,601 9,112 11,881 8,829


The 7th RO.K. Division was reactivated in August 1950, and a U.S. 105 rnm howitzer battalion was attached to each of the seven ROKA divisions to increase their capabilities. The inactivated 2nd and 5th R.O.K. Divisions were reraised later in 1950 along with the new 9th and 11th RO.K. Divisions in October, as was III R.O.K. Corps. The new divisions were authorized 10,400 troops. II R.O.K. Corps was inactivated in January 1951. III RO.K. Corps was inactivated in May 1951. In April 1951, the ROKA requested that it be expanded to 20 divisions, but this was to be delayed by the U.S. as equipment, supplies, and training resources were not available. II R.O.K. Corps was reconstituted in April 1952. Early 1952 again saw proposals for expanding the ROKA to 20 divisions. It was not until November 1952 that the 12th and 15th RO.K. Divisions and 53rd and 55th-59th Independent Infantry Regiments were organized. Fourteen divisions were authorized in February 1953, and the 20th and 21st R.O.K. Divisions were organized followed by the 22nd and 25th RO.K. Divisions in April. The 26th and 27th RO.K. Divisions were raised in June 1953. These divisions did not see combat but conducted rear-area security and continued to train in order to relieve U.S. and U.N. forces that were expected to depart after the coming cease-fire. Maj. Gen. Paik Sub Yup became the ROKA chief-in-staff in July 1952.

At the end of the war the ROKA contained 590,911 troops. The 28th and 29th R.O.K. Divisions, III-VI RO.K. Corps, and First R.O.K. Army Headquarters were organized after the war as U.S. and other U.N. forces returned home. The ROKA emerged from the war as the fourth largest army in the world after the USSR, China, and the United States. (The Capital and 9th RO.K. Infantry Divisions served in Vietnam from 1965/1966 to 1973.)


Unit Designation and Organization Practices


In the early divisions the regiments were assigned at random, while in the later divisions they were assigned in sequential blocks. Regiments were also reassigned between

combat-depleted divisions early in the war. Battalions were numbered Ist-3rd within the regiments. Rifle companies were numbered in sequence throughout the infantry regiment: 1st Battalion-1st-3d Companies, 2d Battalion-5th-7th Companies, 3d Battalion- 8th-10th Companies. There was no "4th Company," and battalion weapons companies were identified by the battalion's designation, for example, Weapons Company, 1st Battalion, 1st R.O.K. Infantry Regiment. Divisional troops battalions and companies were identified by the parent division's number.

In Korean the words "four" and "death" are pronounced the same ("sa") and the number is considered bad luck. For this reason 4 is not used in South Korean unit designations. The North Koreans ignore this superstition. It is also reported that the 14th R.O.K. Infantry Regiment mutinied before the war, the so-called Yosu Rebellion. The R.O.K. Army chief of staff ordered that all units with a 4 in their designation be redesignated as the number gave a unit bad luck and 14th Regiment's rebellion proved it.

The ROKA's normal rank structure for the different echelons of command follows. ROKA officers' ranks were commonly a grade or two lower than the rank of a U.S. Army officer commanding a similar echelon.







brigadier general or major general

colonel or brigadier general

lieutenant colonel or colonel

major or lieutenant colonel

1st lieutenant or captain

2nd lieutenant


The ROKA made some use of task forces, but these were usually temporary regimentalsized or larger groupings formed separately from divisions or from the remnants of combat-depleted units. They were designated with the name of the commander or its location, for example, Task Force Kim or Task Force P'ohang. The division-sized Task Force P'ohang was formed by Eighth U.S. Army at P'ohang on 10 August 1950 to clear enemy forces in the coastal mountains on the northeast comer of the Pusan Perimeter. It was dissolved on 20 August. It consisted of:

17th, 25th, and 26th R.O.K. Infantry Regiments

1st R.O.K. Antiguerrilla Battalion

P'ohang R.O.K. Marine Battalion (provisional)

Battery C, 15th U.S. Field Artillery Battalion (105 mm Howitzer)


 The first two ROKA corps were raised in July 1950 when the ROKA reorganized itself after the initial battles. Other than the R.O.K. Army Headquarters, no higher-echelon headquarters had previously existed to control divisions. Only I R.O.K. Corps served throughout the war's duration. Two to four R.O.K. divisions could be attached to a corps. Initially there were virtually no corps troops. Later, corps troops consisted of maintenance, supply, and medical battalions; a mobile army surgical hospital; and a signal company. Korean corps did not possess a corps artillery until after the war, but U.S. Army field artillery battalions were attached from the Eighth U.S. Army to fulfill that role.


June 25, 1950

Halfway around the glove, another force leavened by combat veterans was also on the move.  On June 25, the North Korean People’s Army (NKPA) stormed across the border into South Korea with nine infantry divisions supported by three-tank regiments.  Many of the 100,000 invaders had fought with the Soviet army against Hitler or with Mao Tse-tung in the Chinese Civil War

They were well armed and well trained.  Their opponent, the Republic of Korea (ROK) Army, was much less ready for battle. 

The United States had equipped the sixty-fie thousand ROK troops with lighter weapons, in part, to prevent the southern President, Syngman Rhee, for carrying out his desire to unify the peninsula by force.  They had 105mm howitzers, 81mm and 60mm mortars, bazookas, light antitank guns, scout cars, and machine guns, but no tanks, fighter planes, or heavy artillery pieces. 

he greater weight of the NKPA told immediately.

June 25, 0600

Long fearful of aggression from the north, the Republic of Korea had built field fortifications along the 38th parallel, but the lightly armed South Korean soldiers proved no match for the Communists. By 0600 hours columns of North Korean infantry, spearheaded by Soviet-built T-34 tanks, drove through the ROK lines toward Kaesŏng in the west and the ROK 6th Infantry Division at Ch'unch'ŏn in central Korea.

On the east coast, south of Kangnung, a motley but effective collection of small boats and junks set Red troops ashore. To U.S. Korean Military Advisory Group (KMAG) field advisers serving with the ROK forces, the Communist assault looked real enough from its outset, but many times before this Red Korean raiding parties had crossed the border. Accustomed to such Communist terror tactics. American observers hesitated to report all-out aggression until they were sure of their facts.