KINTBURY, England — Georges Picquart died 100 years ago this Saturday. To which the response from most quarters is likely to be “Georges who?” Even in his native France, his centenary is passing largely unremarked. Yet in the days of Queen Victoria and Theodore Roosevelt, Picquart was a figure of global controversy, revered and reviled in equal measure as the world’s most famous whistle-blower.

Unlike his 21st-century counterparts Bradley Manning and Edward Snowden, Picquart was neither a disaffected nor a junior figure in the organization he was to expose. On the contrary: In October 1894 he was a brilliant, rising army officer. One of his steppingstones to advancement had been a professorship at the École Supérieure de Guerre, and one of the officer-cadets he had taught there was a Jewish artillery captain, Alfred Dreyfus.

Picquart, like many of his contemporaries, was casually anti-Semitic. It came as no surprise to him when Dreyfus — the only Jew on the general staff — was suspected of passing secret intelligence to the Germans. It was Picquart who provided a sample of Dreyfus’s handwriting to the investigators. And when expert analysis seemed to confirm Dreyfus’s guilt, it was Picquart who met his unsuspecting former pupil in the Ministry of War so he could be quietly bundled off to prison.

In December, Picquart attended Dreyfus’s court-martial as an official observer. For reasons of national security it was held behind closed doors. When told that a file of intelligence evidence existed, conclusively proving Dreyfus’s guilt, Picquart supported the decision to show it in secret to the judges.