Pierre Philippe Marie Aristide Denfert-Rochereau, (French pronunciation:[pjɛʁfilipmaʁiaʁistiddɑ̃fɛʁʁɔʃʁo]; 11 January 1823 – 11 May 1878), was a French serviceman and politician. He achieved fame by successfully defending besieged Belfort during the Franco-Prussian War: this earned him the sobriquet The Lion of Belfort (French: le lion de Belfort).
Born in an upper-class, aristocratic Protestant family, he married a daughter of a leading Montbéliard family, Pauline Surleau-Goguel.
Appointed commander of Belfort in 1870, Colonel Denfert-Rochereau was confronted from November 1870 with the attack and the subsequent siege of the city by the German armies under August von Werder. When asked to surrender the fortress, the Colonel responded: "We are aware of our duty towards France and the Republic, and are resolved to respect it". Refusing to permit the evacuation of the civilian population, in December 1870 the Germans started to shell the city.
Denfert-Rochereau then led with his garrison of 15,000 men (of which only 3,500 were actual soldiers) and the city's population a 103 days resistance against the 40,000 soldiers of Werder. The heroic resistance would eventually end only under the order of the Government of National Defense on the 18 February 1871: Denfert-Rochereau accepted to leave the stronghold with his troops and arms, freely and unconquered, avoiding the humiliation of a defeat.
The resistance of Denfert-Rochereau saved the honour of France, otherwise humiliated by MacMahon's defeat at Sedan and Bazaine' surrender at Metz. It also allowed Thiers to negotiate retention of the Belfort region which thereby was separated from the rest of German annexed-Alsace.
A national hero, Denfert-Rochereau was elected to the National Assembly as a député. There he supported Léon Gambetta's policies. He died in Versailles in 1878, and was buried near his spouse in the Montbéliard Cemetery.