The fourth of seven children of Don Jacolis Rupasinghe Gunawardena, known as Boralugoda Ralahamy, and Dona Liyanora née Gunasekera, he was the younger brother of Harry and Philip.

He attended the government school in Hanwella for his primary education and went on to the Prince of Wales' College, Moratuwa however following his father's false arrest for allegedly being an agitator in the 1915 Ceylonese riots the family decided to withdraw the brothers from the school and enroll them at Ananda College, Colombo.

In the late 1920s Harry, Robert and their younger sister Caroline became active in nationalist youth groups which were demanding democratic reforms with the ultimate goal of complete independence.

[4] In 1931 he campaigned for the Universal suffrage and formed The Cosmopolitan Crew of Lauries Road, Bambalapkiya Association.

The government issued a warrant for Robert's arrest and ordered DIG Sidney Zoysa to kill him or bring him to Army Headquarters.

Robert lost the first general election in 1965, and then received a message from Prime Minister Dudley Senanayake to be an ambassador.