Nazi hockey players salute Hitler before a 1939 match at an English public school.
The German adult touring team extended their arms and shouted "Heil Hitler" as their bemused young opponents looked on.
The moment was captured in a recently-unearthed photo taken at Hitchin Boys' Grammar School, Herts, six months before the Second World War broke out.
Journalist and former pupil Richard Whitmore, who found the snap in a local museum, said: "It sent a shiver down my spine."
The salute was mandatory for Germans at the time. England's football team were even told to join in at a 1938 game in Berlin.