Dominion of Ceylon February 1948, with an amended constitution taking effect on the same date. Independence was granted under the Ceylon Independence Act 1947. Military treaties with the United Kingdom preserved intact British air and sea bases in the country; British officers also continued to fill most of the upper ranks of the Ceylon Army. Don Senanayake became the first Prime Minister of Ceylon. Later in 1948, when Ceylon applied for United Nations membership, the Soviet Union vetoed the application. This was partly because the Soviet Union believed that the Ceylon was only nominally independent, and the British still exercised control over it
Prime Minister of the United Kingdom origins of the position are found in constitutional changes that occurred during the Revolutionary Settlement (1688–1720) and the resulting shift of political power from the Sovereign to Parliament. Although the Sovereign was not stripped of the ancient prerogative powers and legally remained the head of government, politically it gradually became necessary for him or her to govern through a Prime Minister who could command a majority in Parliament. By the 1830s the Westminster system of government (or cabinet government) had emerged; the Prime Minister had become "primus inter pares" or the first among equals in the Cabinet and the head