The British politician and classical scholar J. Enoch Powell (1912-1998) met the French philologist Bertrand Hemmerdinger (1921-2017) in 1948: they shared a common interest in Herodotus and the manuscripts tradition of his Histories. In the present article 11 unpublished letters from Hemmerdinger to Powell (and one letter from Powell to Adams, Librarian of Trinity College, Cambridge) are discussed. These letters – published in the Appendix – shed some new light on Powell’s biography in the years following the end of the Second World War and on his role in shaping Hemmerdinger’s opinion on the textual history of Herodotus (and, in part, Thucydides), but also on Hemmerdinger’s early academic career and the prehistory of his book Les manuscrits d’Hérodote et la critique verbale (1981).