The IV Corps () was a corps of the
Army of the Republic of Vietnam
The Army of the Republic of Vietnam (ARVN; ; french: Armée de la république du Viêt Nam) composed the ground forces of the Republic of Vietnam Military Forces, South Vietnamese military from its inception in 1955 to the Fall of Saigon in April ...
(ARVN), the army of the nation state of
South Vietnam
South Vietnam, officially the Republic of Vietnam ( vi, Việt Nam Cộng hòa), was a state in Southeast Asia that existed from 1955 to 1975, the period when the southern portion of Vietnam was a member of the Western Bloc during part of th ...
that existed from 1955 to 1975. It was one of four corps in the ARVN, and it oversaw the
Mekong Delta region of the country.
The Mekong Delta was the heartland of agricultural South Vietnam, it encompassed the fertile alluvial plains formed by the
Mekong River
The Mekong or Mekong River is a trans-boundary river in East Asia and Southeast Asia. It is the world's twelfth longest river and the third longest in Asia. Its estimated length is , and it drains an area of , discharging of water annuall ...
and its main tributary, the
Bassac River
The Bassac River ( km, ទន្លេបាសាក់; Tonlé Bassac) is a distributary of the Tonlé Sap and Mekong River. The river starts in Phnom Penh, Cambodia, and flows southerly, crossing the border into Vietnam near Châu Đốc. The ...
. With its sixteen provinces, the Delta contained about two-thirds of the nation's population and yielded the same proportion in rice production.
The terrain of IV Corps differed radically from other regions. Flat and mostly uncovered, it consisted of mangrove swamps and ricefields crisscrossed by an interlocking system of canals, natural and artificial. Except for some isolated mountains to the west near the Cambodian border, few areas in the Delta had an elevation of more than above sea level. During the monsoon season, most of the swampy land north of
Route QL-4, generally called the
Plain of Reeds
Plain of Reeds (in vi, Đồng Tháp Mười) is an inland wetland in Vietnam's Mekong Delta. Most of the wetlands are within Long An Province and Đồng Tháp Province.
Physical characteristics
Đồng Tháp Mười is a "back swamp" forming ...
, was inundated, especially when alluvial waters raised the level of the Mekong River from July to October. Other undeveloped swampy areas along the coast had turned into havens that sheltered
Viet Cong
,
, war = the Vietnam War
, image = FNL Flag.svg
, caption = The flag of the Viet Cong, adopted in 1960, is a variation on the flag of North Vietnam. Sometimes the lower stripe was green.
, active ...
(VC) main force units just as the scattered bases inland offered good refuge for local guerrillas.
[
The 7th Division based in ]Mỹ Tho
Mỹ Tho () is a city in the Tiền Giang province in the Mekong Delta region of South Vietnam. It has a population of approximately 169,000 in 2006 and 220,000 in 2012. It is the regional center of economics, education and technology. The majorit ...
was a part of the IV Corps, and due to the division's close proximity to the capital Saigon
, population_density_km2 = 4,292
, population_density_metro_km2 = 697.2
, population_demonym = Saigonese
, blank_name = GRP (Nominal)
, blank_info = 2019
, blank1_name = – Total
, blank1_ ...
was a key factor in the success or failure of the various coup attempts in the nation's history. In the coup attempt of 1960, the loyalist Colonel Huỳnh Văn Cao
Major General Huỳnh Văn Cao (26 September 1927 – 26 February 2013) was a major general in the Army of the Republic of Vietnam.
Life
In 1950, he graduated from Military school in Huế. He then attended College of Tactics and graduated in H ...
used the 7th Division to storm into Saigon to save President Ngô Đình Diệm.
In 1962, Diem decided to split the command of the area in the south around Saigon into two, the former III Corps area being reduced in size to cover the area northeast of Saigon, and the newly created IV Corps taking over the west and southwest. Cao was promoted to general and assumed command of the new IV Corps Tactical Zone, which included the area of operations of his 7th Infantry Division.
ARVN forces under the control of IV Corps consisted of three infantry divisions, two mobile and six border ranger groups. In addition, the territorial forces of MR-4 totaled about 200,000, by far the most numerous among the four military regions. The 7th Division was headquartered at Đồng Tâm Base Camp
Đồng Tâm Base Camp (also known as Đồng Tâm Army Airfield) is a former U.S. Army, U.S. Navy, and Army of the Republic of Vietnam (ARVN) base west of Mỹ Tho in the Mekong Delta, southern Vietnam.
History
1966–9
Đồng Tâm Base C ...
in Dinh Tuong Province Dinh may refer to:
Dinh
''pronounced "zinh" or "yinh"''
*Dinh River (Bà Rịa–Vũng Tàu), river in Bà Rịa–Vũng Tàu, one of five rivers named Sông Dinh in Vietnam.
* núi Dinh, hills in Bà Rịa–Vũng Tàu, Vietnam
Đình
''pronounc ...
; the 9th Division was located in Sa Đéc
Sa Đéc is a Provincial city in Đồng Tháp Province in the Mekong Delta of southern Vietnam. It is a river port and agricultural and industrial trading center. The Sa Đéc economic zone consists of Châu Thành, Lai Vung and Lấp Vò ...
and the 21st Division usually operated in the Cà Mau Peninsula
Peninsula ( vi, Bán Đảo Cà Mau, lnks=no) makes up the southern tip of Vietnam. It is in Cà Mau Province, and lies between the Gulf of Thailand to the west and the South China Sea to the east.
Cà Mau is a triangular stretch of land, with ...
from its headquarters at Bạc Lieu. Despite the substantial combat support and significant advisory effort, both military and civilian, provided by the United States, primary responsibility for the combat effort in IV Corps had always been Vietnamese, even during the period when U.S. units operated in the Mekong Delta.[
]Central Office for South Vietnam
Central Office for South Vietnam (abbreviated COSVN ; vi, Văn phòng Trung ương Cục miền Nam), officially known as the Central Executive Committee of the People's Revolutionary Party from 1962 until its dissolution in 1976, was the Ameri ...
's Resolution No. 9 disseminated in 1969, emphasized the strategic importance of the Mekong Delta and conceived it as the principal battlefield where the outcome of the war in South Vietnam would be decided, the PAVN/VC infiltrated the 1st Division Headquarters and its three regiments, the 88th, 101D and 95A into IV Corps. This effort succeeded despite heavy losses. IV Corps forces were thrown off-balance and the pacification effort declined as a result of extensive PAVN/VC attacks and shellings. Not until after the PAVN/VC's sanctuaries beyond the border had been destroyed during the Cambodian Campaign and their capability to resupply from the sea eliminated were these 1st Division forces compelled to break down into small elements and withdraw. Part of these elements fell back into bases within IV Corps; others retreated toward Cambodia.[
IV Corps was therefore able to regain the initiative during 1971. Its efforts during the year consisted of continuing operations on Cambodian soil to assist the weaker ]Khmer National Armed Forces
The Khmer National Armed Forces ( km, កងកម្លាំងប្រដាប់អាវុធជាតិខ្មែរ; french: Forces armées nationales khmères, FANK) were the official armed defense forces of the Khmer Republic, a ...
and interdicting PAVN/VC supply routes into the Mekong Delta. Concurrently, it also emphasized the elimination of PAVN/VC's bases in the Delta. In addition, they also established a new system of outposts to maintain government control over what had been the PAVN/VC's long-established base areas. The most significant achievements during this period were the neutralization of the extremely heavy enemy
fortifications of Base Area 400 in the That Son
''That'' is an English language word used for several grammatical purposes. These include use as an adjective, conjunction, pronoun, adverb, and intensifier; it has distance from the speaker, as opposed to words like ''this''. The word did not ori ...
(Seven Mountains) area by the 9th Division, the continued destruction of Base Area 483 in the U Minh Forest by the 21st Division, the coordinated activities of the 7th Division and territorial forces in Base Area 470 on the boundary of Dinh Tuong and Kien Phong Provinces, and finally, the successful pacification campaign in Kien Hoa Province Kien or Kiens may refer to:
* Kien, Bern, a village in Bern, Switzerland
* Kien, Burkina Faso, a village
* ''Kien'' (album), a 2008 album by the Japanese group Bleach
* Pine Ridge Airport (ICAO: KIEN), Pine Ridge, South Dakota , US
* Kiens, a c ...
, the cradle of VC insurgency. As a result of these achievements, the situation in IV Corps was particularly bright by early 1972. About 95% of the Delta population lived in secure villages and hamlets. Rice production had increased substantially and education was available to every child of school age. Prospects for the Delta's future looked promising as key government programs such as Land-to-the-Tiller and Hamlet Self-Development were gaining momentum. The four-year Community Defense and Local Development Plan that the government had initiated in March 1972 presaged an even brighter future for the farmers of the Mekong Delta.[
On 3 May 1972 Corps' commander Lieutenant General ]Ngô Quang Trưởng
Ngô Quang Trưởng (13 December 1929 — 22 January 2007) was an officer in the Army of the Republic of Vietnam (ARVN). Trưởng gained his commission in the Vietnamese National Army in 1954 and moved up the ranks over the next decade, most ...
, was appointed commander of I Corps I Corps, 1st Corps, or First Corps may refer to:
France
* 1st Army Corps (France)
* I Cavalry Corps (Grande Armée), a cavalry unit of the Imperial French Army during the Napoleonic Wars
* I Corps (Grande Armée), a unit of the Imperial French A ...
and Major General Nguyễn Vĩnh Nghi assumed command of the Corps.[
]
Divisions
File:ARVN 7th Division SSI.svg, 7th Infantry Division
File:ARVN 9th Infantry Division SSI.svg, 9th Infantry Division
File:ARVN 21st Infantry Division SSI.svg, 21st Infantry Division
References
Corps level formations of South Vietnam
Military units and formations established in 1955
Military units and formations disestablished in 1975
1955 establishments in South Vietnam
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