The British negotiated the island's dominion status with the
leader of the State Council, D.S. Senanayake, during World War
II. Senanayake was also minister of agriculture and vice chairman
of the Board of Ministers. The negotiations ended with the Ceylon
Independence Act of 1947, which formalized the transfer of power.
Senanayake was the founder and leader of the United National
Party (UNP), a partnership of many disparate groups formed during
the Donoughmore period, including the Ceylon National Congress,
the Sinhala Maha Sabha, and the Muslim League. The UNP easily won
the 1947 elections, challenged only by a collection of small,
primarily leftist parties. On February 4, 1948, when the new
constitution went into effect (making Sri Lanka a dominion), the
UNP embarked on a ten-year period of rule.
Data as of October 1988