Brijlal was a soldier in the Bikaner Ganga Risala who served in Mesopotamia, Palestine and France during World War I.

[7] After the war, when it became apparent that India would be an independent nation, he was responsible for the absorption of the state forces into the Indian Army.

[9] In February 1955, Singh was promoted to the rank of lieutenant colonel and appointed commanding officer of the second battalion 3rd Gorkha Rifles (2/3 GR) at Ferozepur.

He moved the battalion to its field area in Jammu and Kashmir in October 1955 and relinquished command in December to attend the senior officers course.

In August 1957, he moved the battalion to Poonch and in November that year, he was posted as a senior instructor at the Infantry School Mhow.

[9] After a 2+1⁄2-year stint, in May 1960, he was promoted to the rank of colonel and posted to Army HQ as deputy director personnel services in the Adjutant-General's branch.

At the age of 42, he immediately earned his maroon beret and his Parachutist badge by making the required number of jumps.

[10][6] In late November 1961, Singh was summoned to the Military Operations directorate at Army HQ for the planning of the liberation of Goa.

The force consisted of 17th Infantry Division, led by Major General Kunhiraman Palat Candeth, which was to move into Goa from the East and 50 Parachute Brigade which was tasked to execute a subsidiary thrust from the North.

[6] Hostilities at Goa began at 09:45 on 17 December 1961, when a unit of Indian troops attacked and occupied the town of Maulinguém in the north east, killing two Portuguese soldiers.

[11] On the morning of 18 December, Singh moved the brigade into Goa in three columns: Although the 50th Para Brigade was charged with merely assisting the main thrust conducted by the 17th Infantry Division, its units moved rapidly across minefields, roadblocks and four riverine obstacles to be the first to reach the capital of Goa, Panjim on 19 December 1961.

On entering the capital, Singh ordered his troops to remove their steel helmets and wear the Parachute Regiment’s maroon berets.

During this stint, on 26 January 1970, Singh was awarded the Param Vishisht Seva Medal for distinguished service of the most exceptional order.

[18] Lt Gen Sagat Singh also conceptualised the Indian Army's first heliborne operation in the Battle of Sylhet[19] He witnessed in Dhaka the signing of the surrender instrument by General Niazi.

For his leadership and command for the race to Dhaka, the Government of India honored Lt. Gen. Sagat Singh with the third highest civilian award of Padma Bhushan.

Unfortunately, he died an untimely death while serving with the battalion in Poonch as a captain on 4 March 1976, when the jeep in which he was travelling met with an accident.