Albrecht Fröhlich was one of the major mathematicians of the latter half of the twentieth century. He will be remembered as one of the few who have succeeded in creating a new subject: he was the creator of Galois module structure, which is now an important branch of algebraic number theory. He died in Cambridge on 8 November 2001, much loved and much honoured. Despite his relaxed persona and happy maturity, his early life was turbulent: he was a Jew, and left school abruptly when he and his family were forced to flee from the Hitler persecution. Thereafter, he completely broke the conventional mould for mathematicians, because he did not attend university till he was very nearly 30 years old and did his most important work when he was nearly 60 years old. He was elected to the Fellowship of the Royal Society in 1976, joining his elder brother Herbert, who had been elected in 1951*.Ali (as he was always called by his friends) was born in Munich on 22 May 1916; he was the youngest of the three children of Julius and Frida Fröhlich, a Jewish couple who hailed from Rexingen in the Black Forest; his sister, Betti, had been born in Rexingen in 1904 and his brother, Herbert, in 1905. He attended Volksschule, and then the Wittelsbacher Gymnasium from 1926 to 1933; his school reports record that his work in history and religion was of outstanding (‘hervorragend’) quality and his work in mathematics and science was praiseworthy (‘lobenswort’), but his English and Latin were poor. In 1933, Hitler came to power, and life became impossible for Jewish families; the Fröhlichs had made no secret of their origins, and Ali made no secret of his opinionsindeed, he joined a Jewish left–wing discussion group* and one day walked home in full view of the Nazi offices with the pockets of his shorts stuffed full of pamphlets. A party of Brownshirts beat up Julius and came looking for Ali. The local policeman, who had an apartment above the Fröhlichs and was still a decent human being, had the presence of mind to arrest Ali as an ‘enemy of the state’. Ali was released the next morning, but the policeman's wife's reaction when she saw Ali was to ask, ‘Are you still here?’. Ali took the hint and left immediately. The people in the French Consulate were very helpful, and by that evening Ali was in Alsace; his father and mother followed soon afterwards.