The Malayan Union was installed in April 1946, but Malay opposition was so strong that by mid-year the British had decided to modify it drastically. In close consultation with UMNO and the rulers, the British drafted plans for the Federation of Malaya (Persekutuan Tanah Melayu). Although the Federation had an effective central government (in contrast with the pre-war situation), the states and the sultans retained a good deal more authority than under the Union, and the citizenship provisions excluded many residents of Indian or Chinese descent. Singapore, with its large Chinese community, continued to be excluded. The Federation was installed in February 1948.
Harper, T.N., The end of empire and the making of Malaya. Cambridge: Cambridge University Press, 1999.
Kahin, Audrey R. Regional dynamics of the Indonesian Revolution: Unity from diversity. Honolulu: University of Hawaii Press, 1985.
Map number from Cribb, Historical Atlas of Indonesia (2000)
Aceh, Bukittinggi, East Sumatra, Jambi, Johor, Kedah, Kelantan, Kuala Lumpur, Labuhan Bilik, Lahat, Malaya, Medan, Melaka, Negri Sembilan, Padang, Pahang, Palembang, Pematang Siantar, Penang, Perak, Selangor, Sibolga, Singapore, Sumatra, Tapanuli, Thailand, Trengganu