The army knew Alfred Dreyfus was innocent and left him on Devil's Island
In 1894 a Jewish artillery captain was convicted of spying for Germany and shipped to a penal colony off South America. The real spy was another officer, Ferdinand Walsin Esterhazy. Army chiefs came to know it, yet chose to protect their reputation rather than free Alfred Dreyfus.
Dreyfus came into the world in Mulhouse, Alsace, on 9 October 1859, youngest of nine children in a prosperous Jewish family whose father ran cotton mills. His mother was bedridden after his birth, so his sister Henriette largely raised him. When Germany annexed Alsace-Lorraine after the war of 1870, the family moved to Basel and later Paris. Seeing his home lost to Germany steered him toward soldiering.
He entered the École Polytechnique in 1877, trained as an artillery officer at Fontainebleau and rose to captain by 1889. In 1891 he married Lucie Hadamard and, days later, learned he had won a place at the War College. There one examiner, General Bonnefond, marked him down on likeability on the grounds that Jews were not wanted on the staff, doing the same to another Jewish candidate. Dreyfus protested, which later counted against him. He still finished ninth and became the only Jewish trainee at General Staff headquarters, though the army as a whole had around 300 Jewish officers.
Once accused, he was an easy scapegoat. The investigation was biased, he was stripped of rank and sent to Devil's Island in French Guiana, and the cover-up grew into a crisis of the Third Republic that exposed antisemitism at the top of army and government. Émile Zola's open letter J'Accuse...! in 1898 revived the campaign by charging military and political leaders with concealing the truth. Supporters included Georges Clemenceau, Jean Jaurès, Anatole France and even the filmmaker Georges Méliès.
Dreyfus was eventually cleared and returned to the army, though at a lower rank than his service deserved. Hatred followed him: at the ceremony moving Zola's remains to the Panthéon, an antisemitic militarist shot at him and was later acquitted. He nevertheless served in the First World War, at Verdun and the Aisne, then retired quietly. He died in Paris on 12 July 1935. Esterhazy was never punished.
Source: Alfred Dreyfus