The self-governance of Singapore was carried out in several stages. After the British joined Singapore once more and started, without much success, dealing with post war problems, Singapore already was not happy with the British as their leaders. Since Singapore's founding in 1819, Singapore had been under the colonial rule of the United Kingdom. The first local elections on a limited scale for several positions in the government of Singapore started in 1948 following an amendment to the Constitution of Singapore. This was further amended with the Rendel Constitution, strengthening local representation. Singapore was granted full internal self-government in 1959, but the colonial administration still controlled external relations and shared control of several key internal policies such as internal security.
In 1963, Singapore joined Malaysia, relieving it of colonial rule and becoming an autonomous state in the Malaysia. After a fallout in the relations between United Malays National Organisation (UMNO) and the People's Action Party (PAP), the ruling parties of the Federation and Singapore respectively, full independence came about with Singapore's expulsion from Malaysia in 1965.
Read more about Self-governance Of Singapore: Yearning For Independence, Partial Internal Self-government (1955–1959), Full Internal Self-government (1959-1963), Campaign For Malaysia