Sir Alexander Oppenheim, OBE FRSE PMN (4 February 1903 – 13 December 1997) was a British mathematician and university administrator. In Diophantine approximation and the theory of quadratic forms, he proposed the Oppenheim conjecture. He was a professor of mathematics at the University of Malaya, the University of Singapore, and its predecessors. During the Second World War, he was a prisoner of war in the Changi Camp and helped organized a "POW University". After the war, he served as the Vice-Chancellor of the University of Malaya before holding two professorships in Ghana and Nigeria. Early life and education Oppenheim was born on 4 February 1903 in Salford, England to an immigrant family from Lithuania. His first language was Yiddish. He grew up in Manchester and attended Manchester Grammar School, where he was recognised as a mathematical prodigy. His teachers considered him too young to attend university and delayed his entrance to scholarship competitions until 1921, when he received a scholarship to Balliol College, Oxford. In each of his three undergraduate years at the University of Oxford, Oppenheim was the Oxford University mathematical scholar. He also captained the university chess team. He graduated with first-class honours in 1924 and was the senior mathematical scholar in 1926. He was awarded a Commonwealth Fellowship to study at Princeton University and the University of Chicago. He completed a PhD at the University of Chicago in 1930 under the supervision L.E. Dickson with a thesis titled Minima of Indefinite Quadratic Quaternary Forms. Oppenheim received a second doctorate, a DSc, from the University of Oxford in 1954 for his academic work later in his career. Career Early career After graduating, Oppenheim spent one year as a lecturer at the University of Edinburgh. He left Edinburgh in 1931 for a professorship at the Raffles College in Singapore. Prisoner of war During the Japanese occupation of Singapore, he served in the Singapore Reserve Army with the rank of lance-bombardier. His wife and young daughter escaped Singapore during this time. He was captured by the Japanese in 1942 and was held as a prisoner of war at Changi Camp. At Changi Camp, Oppenheim helped establish a rudimentary "POW University" with 29 other captured academics and was elected Dean by his fellow prisoners. They had persuaded camp commandant Lieutenant Okazaki to allow them to collect books from Raffles College, hold courses in a dozen classrooms, and organize discussion groups. Oppenheim's