Alwyn Sidney Haynes joined the Malayan Civil Service in 1901. His career included the following posts: Secretary to High Commissioner for Malay States, 1920; Secretary for Agriculture, Straits Settlements and Federated Malay States, and Director of Food Production, 1922; British Resident, Pahang, 1924 and 1926; British Resident, Perak, 1925; British Adviser, Kedah, 1925; Secretary for Postal Affairs, Straits Settlements and Federated Malay States, 1928; Controller of Labour, Malaya; British Adviser, Kelantan, 1930; Colonial Secretary and Member of Executive and Legislative Councils, Straits Settlements, 1933; Lecturer on Malay and on Far Eastern Countries at Oxford University for Colonial Administrative Service Course, 1935-40; Hon. Life Fellow Royal Colonial Institute (now Royal Commonwealth Society), 1916, Member of its Council, 1934 and 1939-54; External Expert on Board of Advisers in Malay, University of London, from 1937, and member of Panel of Additional Lecturers in Malay at School for Oriental and African Studies.