Alec Dakin looked to have a distinguished career as an Oxford Egyptologist ahead of him when he was recruited in 1940 to work as a cryptographer at Bletchley Park. His work as a translator in the German naval section gave him a unique view of the war at sea from May 1940, when he joined, until 1945 .

Among the brilliant group of colleagues who surrounded him were the papyrologist Eric (later Sir Eric) Turner and Leonard Forster, later Professor of German at Cambridge. In charge of the translators in the section was Walter Ettinghausen, who emigrated to Israel after the war. There, as Walter Eytan, he headed the Foreign Ministry, and in 1957 he took the call from the public prosecutor of the German state of Hesse which informed him that Adolf Eichmann was alive and well in Argentina.

After the war Dakin decided not to resume his career as a Fellow of University College, Oxford. Instead, he became a schoolmaster, returning only at the end of his career to Egyptology, but again with distinction.

The son of a sawmaker — his father’s saws were, he said, used to cut the reeds of the Nile — he was born in Mytholmroyd in the West Riding in 1912. He won a scholarship to Heath School, Halifax, and another to Queen’s College, Oxford. There he read Greats and took walks with his fellow Yorkshire scholarship-boy and Nonconformist, Harold Wilson.

With the encouragement of his tutor, Oliver Franks, and the guidance of Professor Battiscombe Gunn, he began the study of Egyptology, and in 1936 he became a Fellow of University College.

As a by-product of his studies he had acquired fluent German, so he was an obvious candidate for recruitment to Bletchley Park. He later described this as the happiest time of his life. He particularly enjoyed the challenge of the early days before the Colossus machine took over the decrypting.

Working in Hut 4, which was responsible for translating the decrypted German naval Enigma signals and processing them for the Admiralty, Dakin often had the job of rapidly identifying which signals were of particular importance. Amid the mass of routine traffic, he recalled such exciting signals as that from the Bismarck: “Most immediate. Torpedo hit right aft. Ship unmanoeuvrable. We fight to the last shell. Long live the Fuehrer.”

Other, more domestic signals from the German Admiralty might dispassionately inform a named and numbered rating on duty aboard a U-boat in the Atlantic that his home, back in Germany, had been total ausgebombt. Finally, Dakin was one of the first people to read the message “The Fuehrer Adolf Hitler is dead.”

Like the other Bletchley Park workers he took an oath of secrecy, and he never spoke to anyone of his war work, not even to his wife, whom he married in 1953. At one point he tried to join the Royal Navy, but he was prevented from doing so on the grounds that he knew too much for the Forces to risk his being captured by the enemy.

With Ernest Ettinghausen, Walter’s younger brother, he wrote a record of the work of Hut 4 for Foreign Office files. This was regarded as so secret that he was not allowed to consult it himself when he came to write his chapter on the work of Hut 4 for Codebreakers (1993), an inside story account of Bletchley Park edited by F. H. Hinsley and Alan Stripp.

After the war he might have returned to his fellowship at Oxford, but instead he took the momentous decision to become a schoolmaster. Having seen so much destruction wreaked upon the civilisation he loved, he thought that he could more directly help to build the world by influencing young people at their most formative stage. In 1946 he joined the staff at Kingswood School, Bath, teaching classics, and he stayed there until his retirement in 1969.

He was for many years a housemaster in the hurly-burly world of a junior house, and was also a highly successful master in charge of athletics. He had a lithe and loping stride and frequently broke into a run as he went about his immensely busy life. With his enthusiasm and patience, his care for the individual, his insatiable curiosity, and his breadth of interest and knowledge he was, like all the best teachers, a walking, often running, advertisement for education. He loved all the arts, had an encyclopaedic memory for poetry in a variety of languages, ancient and modern, and he had the gift of being, in Wordsworth’s phrase, frequently “surprised by joy”.

A friend recalled how, if a pupil turned in a shoddy piece of work the look of cosmic dismay on his usually benign face made the errant boy feel that his lapse had short-changed not just the tutor or the school, but the whole of civilisation.

His retirement was busy. He ran a bookshop in Bath for ten years, he became a Samaritan and worked with autistic children, and he was the first chairman of the National Patient Participation in General Practice. In 1972 the Tutankhamun exhibition led him back to Egyptology, and he started a flourishing class at the North Bristol Institute. He formed links with the Egyptology community at Oxford and Cambridge and gave papers to the Triennial International Congresses at Munich, Turin, Cairo and Cambridge.

His 90th birthday party was attended by an army of friends from many walks of life. He died two months before his golden wedding anniversary.

He is survived by his wife, Joan, and by his two sons.

Alec Dakin, cryptographer and schoolmaster, was born on April 3, 1912. He died on June 14, 2003, aged 91.