Born in Mulhouse, Alsace, France, Dreyfus was the youngest of seven children in the family of a Jewish textile manufacturer who had accepted French nationality in 1871. The family had long been established in Alsace. He was accepted into the École Polytechnique for military training in 1877 and graduated in 1880 as a sub-lieutenant. His entry into the military was very much influenced by the experience of seeing the Prussians enter his hometown in 1871 when he was 11 years old. From 1880 until 1882 he attended at Fontainebleau for more specialized training as an artillery officer. On graduation he was attached to the first division of the 32nd cavalry regiment and promoted to lieutenant in 1885. In 1889 he was made adjutant to the director of the pyrotechnical school in Bourges, and promoted to captain.
On April 18, 1891 he was married to Lucie Hadamard (1870-1945) who would later bear his son Pierre and daughter Jeanne. A mere three days later he received notice that he had been admitted to the Superior War College. Two years later he graduated ninth in his class with honourable mention, and is immediately designated as a trainee at army headquarters where he would be the only Jew. Raphaël, his father, died on December 13, 1893.
At the college examination in 1892, his friends had expected him to do well and be attached to the general staff. However, one of the members of the jury, General Bonnefond, under the pretext that "Jews were not desired" on the staff, lowered the total of his marks by making a very bad report; he did the same thing for another Jewish candidate, Lieutenant Picard. Learning of this injustice, the two officers lodged a protest with the director of the school, Gen. Lebelin de Dionne, who expressed his regret for what had occurred, but was powerless to take any steps in the matter. The protest would later count against Dreyfus.
In an article from the Académie de Poitiers  the author remarks that "Dreyfus was a profoundly patriotic man, and if he had not been the victim of this affair he would certainly have been anti-dreyfusard. He was a haughty, intransigent man, linking very little with his fellow officers. He was a "pisse-froid" as would then have been said in the army." In a report in 1891 on his admission to army headquarters a Colonel Fabre characterized him as "an incomplete officer, very intelligent and capable, but pretentious and whose character in not filling out, and with the conscience and manner required for fulfilling the conditions needed for being employed at army headquarters." This cold personality later proved a deterrent to some of his would-be defenders.
Dreyfus was arrested for treason on October 15, 1894 and the events that follow until his eventual exoneration on July 12, 1906 are chronicled in the article on the Dreyfus affair concerning which he was best known. On January 5, 1895 Dreyfus was stripped of his rank and sentenced to life imprisonment on Devil's Island
From the time of his pardon on September 19, 1899 Dreyfus was at least out of prison. During that time he lived with one of his sisters at Carpentras, and later at Cologny.
The day after his exoneration he was readmitted into the army with the rank of Squadron Chief. A week later he is made a Knight in the Legion of Honour, and subsequently named to the artillery command at Vincennes. On October 15, 1906 he was placed in commend of the artillery unit at Saint-Denis.
Dreyfus' time in prison, notably at Devil's Island, had been difficult on his health, and he was granted retirement in October 1907. He was re-mobilized during World War I when he held assignments in the Paris region.
Dreyfus was present at the translation of Emile Zola's ashes in 1908 when he was wounded in the arm by a gunshot from a disgruntled journalist.
Two days after Dreyfus's death in Paris, France his funeral cortege passed the Place de la Concorde through the ranks of troops assembled for the National Holiday. He was interred in the Cimetiere de Montparnasse, Paris, France.
Publications of Dreyfus