He formed a national government in 1965 and served his third term as prime minister until 1970 during which time he initiated planning for the most ambitious construction projects in Sri Lanka, that of the Mahaweli Development programme.

His paternal grandfather Mudaliyar Don Spater Senanayake established the family wealth through graphite mining, which he later expanded into plantations and investments in the arrack renting franchise.

He grew up in the comfortable family home Woodlands, but was greatly affected by the events of the 1915 riots when his father was arrested by Punjabi soldiers.

[2] Dudley once attended Visakha Vidyalaya, though the exact duration is not confirmed.Dudley received his secondary education at S. Thomas' College, where he excelled in his studies and sports.

Senanayake then went on to Corpus Christi College, Cambridge to read for Natural Science Tripos and after graduation gained admission to the Middle Temple as a barrister.

During this time, he became active in the Ceylon National Congress (CNC), having been appointed in December 1939 as its joint secretary with J. R. Jayewardene, another young lawyer who had been elected to the Colombo Municipal Council.

Four days later, on 26 March 1952, to the surprise of many, Dudley was chosen as prime minister by the Governor-General Lord Soulbury over his cousin Sir John Kotelawala.

Though the UNP remained in power, the Hartal 1953 greatly affected the administration and Senanayake personally, and he resigned as prime minister on health grounds in October, leaving politics and the public limelight.

He supported the efforts of J. R. Jayewardene in establishing UNP trade unions known as Jatika Sevaka Sangamayas and opposed nationalization of insurance companies and the Colombo port by Bandaranaike.

He had narrowly missed an assassination attempt on 23 March 1965 when a bomb was thrown into Esmond Wickremesinghe's house moments after Senanayake had left the premises while negotiations were underway to form a government.

They were later acquitted of a plot to overthrow the legally elected government, which greatly discredited the Senanayake administration, along with the bribery trail of Dr. Mackie Ratwatte, brother and former personal secretary of Sirimavo Bandaranaike.

However, the UNP was thrown from office after the United Front coalition (SLFP, LSSP, and the Communists) led by Sirimavo Bandaranaike won a large majority of 91 seats.

He is remembered for carrying forward his father's legacy, especially in the areas of agricultural reforms and large-scale projects, introducing his own, and initiating more such as the Mahaweli development programme.

His foreign policy was pro-western, yet he maintained good relations with communist countries such as China, establishing the Ceylon-China Trade Agreement of 1952.

Dudley Senanayake's funeral took place at Independence Square, where J. R. Jayewardene, delivering a moving speech, ended it by saying "Good night sweet Prince".