From Lankaweb, Youtube.
Senanayake played an active role in the independence movement first supporting his brother Fredrick Richard Senanayake and after his death in 1926, D. S. took his place Legislative Council and lead the independence movement. In 1931 when he was elected to the State Council, and went on to become Minister of Agriculture and Lands. He combated Ceylon’s agricultural problems effectively, and established the LDO, an agricultural policy that countered Ceylon’s rice problems. This policy earned him respect, and he continued to be a minister for fifteen years. He also enforced “Agricultural Modernisation”, which increased production output. During World War II he was a member of the Ceylon war cabinet.
However, he resigned in 1946 from his cabinet post to fight for Ceylon’s independence. That same year he founded the United National Party (UNP) by amalgamating three right-leaning pro-dominion parties, which is still one of the main political parties and perhaps the largest single party in Sri Lanka. In only a year he succeeded, and was elected as Ceylon’s first Prime Minister in the general election held in 1947. He refused a knighthood, but maintained good relations with Britain and was a Privy Councillor. He boldly made plans to spread out the population, and his Gal Oya scheme relocated over 250,000 people.