He was born at Rennes, entered the army in 1856, and served in Algeria, Italy, Cochin-China and the Franco-Prussian War, earning a reputation. He was made a brigadier-general in 1880, on the recommendation of the duc d'Aumale, then commanding the VII army corps, and Boulanger's expressions of gratitude were held against him later when, as war minister in de Freycinet's cabinet, he erased the name of the duc d'Aumale from the army list, as part of the republican campaign against the Orléanist and Bonapartist princes. In 1882 he was appointed director of infantry at the war office, enabling him to make himself known as a military reformer; and in 1884 he was appointed to command the army occupying Tunis, but was recalled owing to his differences of opinion with Cambon, the political resident. He returned to Paris, and began to take part in politics under the aegis of Georges Clemenceau and the Radical party; in January 1886, when Freycinet was brought into power by the support of the Radical leader, Boulanger was given the post of war minister.
By introducing genuine reforms for the benefit of officers and common soldiers, and by his quest for popularity -- shown in his aggressive attitude towards Germany in connexion with the Schnaebele frontier incident of 1887 -- Boulanger came to be regarded as the man destined to give France her revenge for the disasters of 1870. He was used simultaneously as a tool by the anti-Republican intriguers. Boulanger was taunted in the Senate with his ingratitude to the duc d'Aumale, and denied that he had ever used the words alleged. His letters containing them were published, and the charge was proved. Boulanger fought a bloodless duel with the baron de Lareinty over this affair, but it did not affect his popularity, and on Freycinet's defeat in December 1886 he was retained by René Goblet at the war office. Clemenceau, however, had abandoned his patronage of Boulanger, who was becoming so prominent that, in May 1887, Goblet got rid of him by resigning. The mob clamoured for their "brave general," but Maurice Rouvier, who next formed a cabinet, declined to take him as a colleague, and Boulanger was sent to Clermont-Ferrand to command an army corps. A Boulangist "movement" was now in full swing. The Bonapartists had attached themselves to the general, and even the comte de Paris encouraged his followers to support him. His name was the theme of a popular song -- "C'est Boulanger qu'il nous faut"; the general and his black horse became the idol of the Parisian populace; and he was urged to become a plebiscitary candidate for the presidency. The general agreed.
However, after various symptoms of insubordination had shown themselves, he was deprived of his command in 1888 for twice coming to Paris without leave, and finally on the recommendation of a council of inquiry composed of five generals, his name was removed from the army list. He was, however, almost at once elected to the chamber for the Nord, his political programme being a demand for reform of the constitution. In the chamber he was in a minority, and his actions were directed to maintaining his public image. Neither his failure as an orator nor his defeat in a duel with Floquet, then an elderly civilian, reduced the enthusiasm of his popular following. During 1888 his personality was the dominating feature of French politics, and, when he resigned his seat as a protest against the reception given by the chamber to his revisionist proposals, constituencies vied with one another in selecting him as their representative.
In January 1889, he was returned for Paris by an overwhelming majority. Boulanger had now become a threat to the parliamentary Republic. Had he immediately placed himself at the head of a revolt be might have effected the coup d'état which the intriguers had worked for, and might even have governed France; but the opportunity passed. The government, with Constans as minister of the interior, had been preparing a prosecution against him, and within two months a warrant was signed for his arrest. To the astonishment of his friends, on April 1 he fled from Paris before it could be executed, going first to Brussels and then to London. It was the end of the political danger, though Boulangist echoes continued for a little while to reverberate at the polls during 1889 and 1890. Boulanger himself, having been tried and condemned in absentia for treason, went to live in Jersey, but nobody now paid much attention to him. The world was startled by the news that he had committed suicide in a cemetery at Brussels by blowing out his brains on the grave of his mistress, Madame de Bonnemains (née Marguerite Crouzet), who had died in the preceding July.
See Verly, Le Général Boulanger et la conspiration monarchique (Paris, 1893).