Kurt was the youngest of Robert and Anna Hirsch's five children, having four older sisters. In 1913, when Kurt was seven years old, his father's soap factory failed. The family had been well off but now there was a sudden change in their fortunes. Unable to cope with the collapse of his business, Robert committed suicide. The blow of losing his father was too much for Kurt and his behaviour became extremely difficult. He was sent to a boarding school in Frankfurt-an-der-Oder - the Humanistischen Staatlichen Friedrich-Gymnasium. He completed his education at the school in 1924 but his family were in no position to support him while he took university studies. At this stage he benefited from having August Hirsch as his grandfather, for the University of Berlin were prepared to offer a scholarship to the grandson of a former distinguished rector of the university. Kurt Hirsch began his studies there in the autumn of 1925, taking courses in both mathematics and philosophy.
At the University of Berlin he was taught mathematics by, among others, Bieberbach, von Mises, Schmidt and Schur. Although most influenced by Schur, his doctoral dissertation Intuition und logische Form. Zur gegenwärtigen Philosophie der Mathematik was on the philosophy of mathematics. The thesis examines the 1920s dispute between Hilbert and Brouwer on the foundations of mathematics. Completed and examined on 10 June 1930 (Bieberbach was an examiner), it was not until 1933 that Kurt could afford to get it printed, so he did not receive the degree until 1933. Part of the reason for his poor financial position was his marriage in 1928 to Elsa Brühl. By the time he passed his oral examination they had one son Daniel (born 1929) and the scholarship he received was quite insufficient to support a wife and child let alone pay the extra expense of getting a thesis printed.
In order to be able to support his family, Kurt became a journalist in 1928, writing a scientific column for the Vossische Zeitung. This liberal newspaper, published in Berlin, was a highly respected one which had published since the early 18th century. However he kept up his mathematics attending a study group where he studied Emmy Noether's work and read Schreier's paper on the Jordan-Hölder theorem. Influenced by these ideas he decided to study soluble groups with the maximum condition on subgroups. From the time he began working for Vossische Zeitung until the Nazis came to power in 1933 he established an increasingly significant role with the paper. He was given complete editorial control over his weekly column, and as well as articles which he wrote himself, he also was able to get top scientists such as Heisenberg and Schrödinger to contribute articles.
On 30 January 1933 the National Socialist party led by Hitler came to power in Germany. On 7th April 1933, Hitler introduced a law for the "Restoration of the civil service". This meant that all non-Aryans and Jewish civil servants were dismissed from their positions with the exception of those who either had fought in the Great War or had been in office since August 1914. The Nazis could not accept the liberal Vossische Zeitung and, after a difficult year of tension, they closed the paper down on 31 March 1934, replacing it with their own paper the Völkischer Beobachter. Kurt's wife was Jewish and he had adopted the faith for her sake. Having lost his job and seeing the way that the Nazis were treating German Jews, he had little choice but to leave for England (where he had distant relatives). By this time Kurt and Elsa had a second child, Sabine who was born in 1932. He left his wife and family in Berlin and set out for England. On arriving in London in April 1934 he was met by Bernhard Neumann and Hanna von Caemmerer (later to become Hanna Neumann who was visiting Bernhard). He had known Bernhard as a fellow student in Berlin. Kurt was introduced to Philip Hall who strongly encouraged him to pursue his intention of working on soluble groups with the maximum condition on subgroups. Up to this stage Hirsch had been totally undecided whether to pursue mathematics or journalism as a career but his meeting with Hall quickly led to him choosing mathematics.
Despite having a doctorate, Hirsch decided that his prospects in Britain would be better if he had a British doctorate so he became a student of Hall. He studied at King's College, Cambridge, obtaining financial support from the university. In September 1934, Elsa, Daniel and Sabine left Berlin and joined Hirsch in Cambridge where he had rented a house close to where Bernhard Neumann was living. Hirsch published his first paper A note on non-commutative polynomials in 1937. He completed his second doctoral thesis A Class of Infinite Soluble Groups in 1937 in which he studied soluble groups with the maximal condition on subgroups, now called polycyclic groups. In the final chapter of his thesis he studied skew-groups which are finitely generated torsion free groups with cyclic centre which contains the derived subgroup. He wrote up this part of his thesis as a paper and On skew-groups was published in the Proceedings of the London Mathematical Society in 1939. Two papers On infinite soluble groups I and II which were related to his thesis had been published in the same journal in 1938.
Appointed to Leicester in 1938 he was interned as "an enemy alien" in 1940. In May 1940 Winston Churchill led a newly formed coalition government which decided that all enemy alien's were to be interned. Hirsch was sent to the Central internment camp in Douglas on the Isle of Man, where he lived in House 7. He worked there as a cook (and retained an interest in recipes all his life) but conditions were reasonable and he was able to take country walks supervised by an armed guard. The internees organised concerts. lecture courses and a camp university in which Hirsch was happy to participate. He was soon released, however, mainly due to strong pressure from the Vice-Chancellor of Leicester and returned to his position in the university in October 1940. His position was only a temporary one and it remained so for four years until it was made permanent in 1944. That he had interests outside mathematics is illustrated by the fact that he was Leicester County Chess Champion in 1945-46. His third paper A Class of Infinite Soluble Groups was published in 1946. In 1947 both Kurt and Elsa became British citizens.
In 1948 Hirsch moved to King's College, Newcastle (founded in 1937 as a part of the University of Durham and becoming the University of Newcastle in 1963) where he worked under the newly appointed professor of Pure Mathematics, W W Rogosinki. Alfred Goldie wrote about Hirsch's time in Newcastle :-
It was a wonderful atmosphere, [Rogosinki and Hirsch] knew what a real university was about and set out to create a microcosm of it in pure mathematics. Bonsall and I shared a room next to Kurt but the rooms had a common phone reached through a hatch. [Kurt], of course, used it almost exclusively, having all sorts of business to transact. His personality made an impact rather stronger than that of Rogosinki, though one could see that Kurt regarded Rogosinki as more important than himself on the only ground that mattered to Kurt, namely mathematical standing. He had a calm judgement in such matters.While at Newcastle he began translating Kurosh's The theory of groups into English, a project he was to work on for a number of years. He was a leading reformer of the mathematics syllabus at Newcastle where again he found time to win the County Chess Championship in 1950.
Then in 1951 Hirsch was appointed to Queen Mary College of the University of London where he was appointed professor in 1958. He remained there for the rest of his career, building up a strong algebra school. He sought Hall's advice in appointments of algebraists and attracted many research students to make a thriving group theory school. In  Gruenberg writes:-
Hirsch was a shrewd judge of people and managed to create at Queen Mary College an unusually friendly environment for students as well as staff. Everyone felt encouraged to be cooperative. Younger members of staff found him easy to work with and knew they could count on his help and protection. He gave them generously of his time with sound advice on teaching, on examining and on supervising research students.All Hirsch's publications were in group theory, in addition to the work on polycyclic groups he published on locally nilpotent groups and automorphism groups of torsion free abelian groups. Some of his later publications are (with Terry Hallett) Groups of exponent 4 as automorphism groups (1970),and Finite groups of exponent 12 as automorphism groups (1977). His translation of the first volume of Kurosh's The theory of groups into English was published in 1955, with the second volume in the following year. He had spent 1954-55 as visiting professor at the University of Colorado and given a course covering the whole of the first volume in two semesters lecturing at three lectures per week. It was the first of many translations from Russian to English that he made. Other include: F R Gantmacher, The theory of matrices. Vols. 1, 2 (1959); A G Kurosh, Lectures on general algebra (1963); I M Gelfand, M I Graev and I I Pyatetskii-Shapiro, Representation theory and automorphic functions (1969); A D Aleksandrov, A N Kolmogorov and M A Lavrent'ev (eds.), Mathematics: Its content, methods, and meaning. Vol. III (1969); B I Plotkin, Groups of automorphisms of algebraic systems (1972); I R Shafarevich, Basic algebraic geometry (1974); D A Suprunenko, Matrix groups (1976).
Article by: J J O'Connor and E F Robertson