Walter Ledermann was born on 18 Mar 1911, the second of William and Charlotte Ledermann's four children, in Berlin, Germany. His Father was a physician, though the family was accustomed to poverty following World War I and the depression of the 1920s.
Ledermann was a promising student from an early age, and a keen violinist. He received his leaving certificate from the Leibniz Gymnasium early due to his performance in classics and mathematics, which allowed him to complete his degree in Mathematics and Physics at the University of Berlin. There he encountered several mathematicians and physicists of note who inspired him, including Issai Schur, Heinz Hopf, Max Plank, and Erwin Shrodinger.
On completion of his degree, it became clear to Ledermann that he could no longer stay in Germany. He won a scholarship created by students at St Andrews to support a Jewish refugee, during which time his brother was working in Edinburgh to gain a medical qualification. Ledermann was awarded his PhD after two years.
Encouraged by Professor Turnbull of St Andrews University, Ledermann sought an interview with Professor Edmund Whittaker (later Sir) at the University of Edinburgh with a view to seeking employment there. Whittaker invited him to come as a visiting student to Edinburgh for one term, offering him a bursary of £50 and encouraging him to attend the lectures of A C Aitken. Aitken quickly became a friend to Ledermann, and introduced him to Godfrey Thomson, Bell Chair of Education at the University of Edinburgh, and Director of Edinburgh Provincial Training Centre (later Moray House College of Education).
At that time, Thomson required a mathematical assistant for a Carnegie funded project which would eventually result in the publication of his seminal book, The Factorial Analysis of Human Ability, and he immediately offered Ledermann the post. It is from this period that the majority of Ledermann's papers, which largely comprise of letters from Thomson, were created.
Ledermann's work with Thomson was interrupted for 6 months in 1937 when Ledermann accepted a post teaching at the University of Dundee. He returned to work with Thomson in Edinburgh until 1938, when he took a lecturer's post in the University of St Andrews.
In 1940, Ledermann's naturalization was completed, and he was also awarded his DSc from the University of Edinburgh. He married his wife, Ruth Ledermann, a social worker, in 1946, later having a son, Jonathon. The couple moved to Manchester, where Ledermann was worked as a lecturer in pure mathematics in the University of Manchester, from 1946-1962.
In 1962 Ledermann gained a lecture post at the new University of Sussex, where he eventually became a professor. He found the atmosphere of the modern university highly stimulating, and taught for two further years past the statutory age of retirement (then 65). Even after his official retirement in 1978, Ledermann continued to give occasional courses and revision classes to his students until 1997, when he and Ruth, by then a psychotherapist, moved to London.
Ledermann died in London on 22 May 2009.