The Malaysian citizenship regime is shaped by British colonialism, federalism, the politics of communalism and ethnic nationalism. Ius soli has been controversial in Malayan citizenship history due to the immigration history of British Malaya. Birthright citizenship for many generations of immigrants was contested because they were not readily assimilated into the Malayan way of life, which challenged the ethnic homogeneity of Malay nation-states. The adoption of territorial birthright principles was contested in the post-war period due to the emergence of politics of communalism and ethnic nationalism. As ius soli has been controversial in Malayan citizenship history, the Federation of Malaya (1948) resorted to the principle of double ius soli, followed by the principle of delayed ius soli in 1952 before fully institutionalising unconditional ius soli on the eve of Malayan independence in 1957.