The 1st Infantry Division of the Army of the Republic of Vietnam (ARVN)—the army of the nation state of South Vietnam that existed from 1953 to 1975—was part of the I Corps that oversaw the northernmost region of South Vietnam, the centre of Vietnam.
The 1st Infantry Division was based in Huế, the old imperial city and one of two major cities in the region, which was also the corps headquarters. Until late 1971 the division was also tasked with the defence of Quảng Trị, the closest town to the Vietnamese Demilitarized Zone (DMZ) and among the first to be hit by the Tet Offensive.
History The division had its origins in the 21st Mobile Group, raised by the French for the State of Vietnam in Thừa Thiên and Quang Tri, and formally established 1 September 1953. The Mobile Group provided the nucleus for the 21st Infantry Division. In January 1955 the 21st Field Division (commanded initially by Lieutenant Colonel Lê Văn Nghiêm) was established. On 1 November 1955 it was redesignated as the 1st Field Division and then redesignated as the 1st Infantry Division in January 1959.
1964 On 20 September during Operation Lam Son 129 elements of the ARVN 2nd Battalion, 1st Infantry engaged two Vietcong (VC) companies near the village of Le Xuyen, about 10km from Quang Tri. Two platoons of M113 armored personnel carriers attacked from the south and infantry blocked the VC's escape to the north. After an airstrike in which the VC shot down a Republic of Vietnam Air Force (RVNAF) A–1H, they tried to withdraw eastward into rice paddies inundated with waist-deep water. The M113s pursued them and the ARVN killed 77 VC and captured 11 along with three light machine guns and 73 individual weapons. ARVN losses were one dead and seven wounded. At least one of the captives was a North Vietnamese who had just arrived in South Vietnam four days earlier. The Saigon government claimed both companies were elements of the PAVN, a statement MACV denied.
On 26 November the division engaged a VC battalion south of Cam Lộ district. The operation resulted in one ARVN killed and 18 wounded, while the VC lost 73 killed (22 confirmed by American advisers) and three light machine guns, an antiaircraft machine gun, two 60mm mortars, and a 57mm recoilless rifle.
On 14 December a VC battalion attacked Thon La Chu, 3km southwest of Huế. The 1st Battalion, 51st Infantry attacked An Do hamlet but were unable to advance and withdrew to allow airstrikes and artillery fire. The VC evacuated An Do overnight. The battalion fought its way into Bon Tri hamlet, but then withdrew for the night. Again the VC evacuated overnight. ARVN loses were 12 dead and 39 wounded and one US adviser killed. VC losses were 58 killed and nine captured.
1965 On 7 January a VC company attacked a Popular Forces platoon camped 6km southeast of Huế. A second Popular Forces platoon was ambushed going to their aid. A reaction force of a Regional Forces company, a rifle company, a troop of M113s, and part of the division's elite Black Panther Reconnaissance Company joined the battle. The fighting was at such close quarters as to prevent fixed-wing aircraft and US Army helicopter gunships from lending support. A second M113 platoon arrived and assaulted the VC flank. When the South Vietnamese searched the battlefield the next morning, they found 50 VC dead, a 60mm mortar, three light machine guns, and 11 rifles. The relief force lost four dead, four missing, and two carbines.
On 12 January the 1st Infantry Regiment encircled an 80-man Local Force VC company 8km west of Quảng Trị. The ARVN killed 32 VC and captured four prisoners and 19 weapons.
On 10 February in order to counter a VC campaign of assassination, terror, and sabotage in two coastal districts 10km southeast of Huế, the 3rd Infantry Regiment sent a battalion, an additional rifle company, an M113 troop, a Popular Forces platoon, and two howitzer platoons to secure the area. By 1 March, these tactics had killed five VC and captured a Front district leader, twelve VC, and supply caches. Intelligence then indicated that a VC company had fortified itself in a village and the 3rd Infantry commander immediately launched an attack that killed 24 VC, captured six more along with 17 suspects, and seized several weapons, including a 60mm mortar. The 3rd Infantry then returned to original operational area, killing another 50 VC, mostly by artillery fire, and captured a mortar and 26 individual weapons.
On 6 March VC mortars bombarded Quang Tri. When the commander of the 1st Infantry led four M113s to find the mortars, the VC ambushed the column 1km west of the city. An antitank weapon destroyed the command vehicle, killing the regimental commander, his deputy, and three other soldiers.
On 13 April a VC battalion attempted to ambush three division battalions along Highway 1 at the border of Quang Tri and Thua Thien provinces. Forewarned, the ARVN avoided the trap but lost the initiative by waiting for air and artillery strikes to have an impact on the VC. The strength of the VC positions, communication difficulties, and several incidents in which a US Army gunship, an American jet, and a Vietnamese M113 fired on friendly troops complicated the situation. In the daylong action, VC forces killed 8 ARVN and wounded 37 and destroyed two M113s. Allied air and artillery fire reportedly killed 30 civilians and destroyed 74 houses. Five VC bodies were found and residents reported that the VC had carried off another 40 dead.
On 29 May in the Battle of Ba Gia the Division's 1st Battalion, 51st Regiment was ambushed by VC as it attempted to relieve a South Vietnamese Regional Force (RF) unit in the village of Phuoc Loc. In less than one hour of fighting, the battalion was completely destroyed with 270 soldiers either killed or wounded and 217 men were captured. Only 65 ARVN soldiers and three American advisors managed to return to government lines. On the afternoon of 29 May III Corps commander Thi formed a Task Force consisting of the 2nd Battalion, 51st Regiment, the 3rd Marine Battalion, the 39th Ranger Battalion and one squadron of M113s to recapture Ba Gia. On the morning of 30 May the Task Force assembled in Quảng Ngai and following extensive air support from US fighter-bombers and helicopter gunships the force advanced towards their objectives in two separate columns. The VC first attacked the 2nd Battalion, 51st Regiment and then ambushed the 3rd Marine Battalion as it attempted to support the 2/51st forcing both units to retreat to Phuoc Loc. On the morning of 31 May the VC renewed their attacks capturing Phuoc Loc and attacking the 39th Rangers inflicting heavy casualties.
Also on 29 May the VC assaulted a Regional Forces company outpost at Khe Tre, Thua Thien province, 56km northwest of Da Nang. After a VC battalion captured the post, the division organized a reaction. The 1st Battalion, 3rd Infantry was landed at Nam Dong, 8km south of Khe Tre and then began moving north. After splitting the battalion into two columns with half on the road and the other half advancing cross country, the offroad column soon fell behind those on the road, as the terrain was mountainous and choked with vegetation. At 13:30 the VC opened fire on the road column, popping out of spider holes placed 30 meters from the road. The lead South Vietnamese company broke into a run toward Khe Tre, abandoning the rest of the battalion. The battalion headquarters company also ran, this time toward Nam Dong. Left alone on the road to fend for themselves were the battalion commander and his two advisers. The two offroad companies also received fire. Although this fire was light, VC gunners managed to kill or wound both company commanders and several noncommissioned officers. Leaderless, the troops withdrew in disorder. US Army gunships attacked VC positions on overlooking ridge lines, but did not fire close to the ARVN for fear of hitting them. After the VC killed the battalion commander and wounded the senior adviser, the remnants dissolved. Early on 30 May the 3rd Battalion, 3rd Infantry and the elite Black Panther Company were landed at Nam Dong. They explored the VC's 1km-long ambush position, finding no bodies. The ARVN had lost 29 dead, 26 wounded, including one American, and 30 missing. It also had lost 87 weapons.
On 1 July the division used an M113 troop, a Regional Forces company, and four Popular Forces platoons to react to an attack in Thua Thien province by two VC companies. VC losses were 92 killed and 18 captured along with 25 weapons and two mortars. ARVN losses were seven dead and six missing.
In late 1965 Major general Lewis William Walt, the commander of the US III Marine Amphibious Force and the I Corps' senior adviser, assessed the division under General Nguyễn Văn Chuân as "waging a skillful campaign" and "consistently destroying the VC in all significant encounters."
1966-1967 On 12 March 1966 following the dismissal of General Nguyễn Chánh Thi as I Corps commander, Chuân was appointed as the new I Corps commander and General Phan Xuân Nhuận, the head of the Ranger Command in Saigon, was given command of the division. Following the dismissal of Thi, the northern zone erupted into a seething inferno of political dissent in the Buddhist Uprising. The number and intensity of strikes, marches, and rallies steadily increased, fueled by soldiers, police, and local officials loyal to Thi. By the beginning of April Struggle Movement forces appeared to control most of Huế, Da Nang and Hoi An and had the support of the I Corps headquarters and the division. At the same time, South Vietnamese combat operations in the northern zone began to peter out, and the danger that the crisis presented to the war effort became evident. As the new division commander, Nhuận placed infantry and armored forces in blocking positions along Route 1, between Huế and Da Nang, and stood ready to reinforce Struggle units in Da Nang the situation inside the city was tense. The commander of the Quang Nam Special Zone, Colonel Dam Quang Yeu, headed the rebel military units that, according to US estimates, included an infantry battalion from the 51st Regiment, three Regional Forces companies, eleven Popular Forces platoons, and six armored vehicles, plus about 6000 South Vietnamese administrative troops and 200 military police. When Yeu quickly positioned some of his units on the approaches to the downtown area, the start of civil war seemed imminent.
On 10 June 1966 the South Vietnamese junta began a steady buildup of special riot police under Republic of Vietnam National Police commander Colonel Nguyễn Ngọc Loan on the outskirts of Huế and, on 15 June, sent a task force of two Airborne and two Marine battalions under Colonel Ngô Quang Trưởng into the city for a final showdown. Intermittent fighting lasted in Huế for four days. Opposition was disorganized and consisted of about 1,000 division troops, mostly soldiers from support units. Protected by Trưởng's forces, Loan's police removed the Buddhist altars and arrested most of the remaining leaders of the Struggle Movement, including Thích Trí Quang. The junta gave Trưởng command of the division, and by the end of June both the division and Huế were under firm government control. By 1967 US advisers reported that Trưởng had whipped the formerly rebellious division into one of South Vietnam's best army units.
In mid-July 1966 the division launched Operation Lam Son 289 in support of the US 3rd Marine Division's Operation Hastings in the southern DMZ. The division lost 21 killed in the operation.
From 18–26 May 1967 the division conducted Operation Lam Son 54 in coordination with the US 3rd Marine Division's Operation Hickory near Con Thien.
1968 By 1968 the Division's 1st Regiment was responsible for Strongpoint A-1 () part of the Strongpoint Obstacle System south of the DMZ.