The Dreyfus Affair began when Alfred Dreyfus, a Jewish artillery officer in the French Army, was accused of passing military secrets to Germany. In October 1894, a document known as the bordereau was discovered that implicated Dreyfus, leading to his arrest and subsequent trial. The evidence presented against him was weak and based largely on forged documents, yet he was convicted in December by a military court. Amid rising anti-Semitic sentiment in France, Dreyfus's trial was marked by scandal and significant public outcry.

Following his conviction, the case attracted the attention of prominent intellectuals, including writer Émile Zola, who famously published an open letter titled "J'accuse...!" in which he accused the French government of anti-Semitism and the miscarriage of justice. This letter brought the case into the public eye and led to widespread protests demanding a retrial. The Dreyfus Affair divided French society, splitting it between the pro-Dreyfusards, who fought for justice, and the anti-Dreyfusards, who were resistant to change and often steeped in nationalist and anti-Semitic beliefs.

Eventually, in 1899, Dreyfus was granted a retrial, but he was again found guilty, albeit with extenuating circumstances. It wasn't until 1906 that he was fully exonerated, and he returned to the army, becoming a symbol of the fight against injustice. The entire affair prompted discussions about civil rights, the integrity of the military, and the pervasive influence of anti-Semitism in Europe, setting a precedent for future human rights movements.