1st Battalion, Royal Australian Regiment

In 1945 Australia sent three units to Japan as part of the British Commonwealth Occupation Force (BCOF). Originally known as the 65th, 66th and 67th Infantry Battalions, they were raised from Australian divisions stationed in New Guinea at the end of the Second World War. On 23 November 1948, the battalions were renamed the First, Second and Third Battalion, The Australian Regiment, respectively. The prefix "Royal" was granted by King George VI on 31 March 1949.

Prior to its departure, 1RAR was based at Holsworthy barracks, Sydney. It arrived in Vietnam throughout March-June, 1965. It was deployed to the United States Bien Hoa Air Base in Bien Hoa province. It was the third infantry battalion attached to the US 173rd Airborne Brigade (Paratroopers).

Initially, 1RAR was restricted to security operations defending the airbase. However, in September 1965, the Australian government lifted these restrictions, and 1RAR was able to be fully employed as a manoeuvre battalion. It participated in search and destroy missions, patrolling and security operations. 1RAR's patrol program reduced enemy activity around the Bien Hoa Airbase to an all-time low.

In early 1966 1RAR was involved in Operation Crimp (8-14 January). This was a search-and-destroy operation in the Hobo Woods, north of Saigon. During Crimp, 1RAR uncovered the Cu Chi tunnel complex. A search of the tunnels resulted in the capture of thousands of documents, weapons and supplies.

As a result of its successful patrolling tactics, 1RAR was asked by the US 1st Infantry Division ("The Big Red One") to participate in Operation Rolling Stone (19-26 February). The battalion provided security for US army engineers who were building a road. Once the operation had finished the battalion returned to the 173rd Airborne Brigade.

1RAR was relieved by the First Australian Task Force (1ATF) during May-June 1966. It returned to Australia in June.

1RAR returned to Vietnam for a second tour, relieving 7RAR on 9 April 1968. It was based at Nui Dat in Phuoc Tuy province, and was primarily involved in patrols, searches, reconnaissance and security operations.

On 12 May 1RAR was redeployed north of Saigon for Operation Toan Thang (21 April - 7 June). This operation aimed at blocking the communist withdrawal following the 1968 Tet Offensive. 1RAR patrolled the Bien Hoa-Bien Nuong border. On 11 May the battalion arrived at Fire Support Base Coral. The base was attacked twice, firstly on 13 May and again on 16 May. Both attacks were repulsed. On 6 June Coral was closed, and 1RAR returned to Nui Dat.

A follow-up operation, Toan-Thang II (13 June - 18 July 1968), saw the battalion move to the Bien Hoa-Long Khanh border. 1RAR participated from 13 June to 3 July.

The battalion continued to carry out patrolling operations in Phuoc Tuy province for the remainder of its second tour. It was replaced by 5RAR on 15 February 1969. 1RAR departed for Australia the following day, arriving in Sydney on 28 February.

The 173rd Airborne Brigade (Separate) to which the 1st Battalion, Royal Australian Regiment and supporting units were attached, was awarded the Republic of Vietnam Cross of Gallantry with Palm unit citation for the formation's service from the 6th of May 1965 to the 31st of May 1966. Though 1RAR was attached to the 173rd Airborne Brigade as the third battalion and served in seven of the Brigade's operations, due to government policy on the acceptance of foreign awards, the award was not automatically conferred to the Australians.

On the 11th of May 2015, following a three year review by the Defence Honours and Awards Appeals Tribunal, 1RAR was retrospectively awarded the Republic of Vietnam Cross of Gallantry with Palm unit citation.