Dogs have accompanied men to war since ancient times, as scouts, sentries, trackers and messengers. But the most unique role they ever played was that of the “mercy dog” in World War 1, seeking out wounded soldiers in no man’s land where medics can’t reach them, comforting the mortally wounded and offering companionship and respite to those dying for their country.

French medical dog tracks down a wounded man. Postcard, 1914. Photo: Frankfurter Allgemeine