During the French Revolution, Milhaud took part in the Storming of the Bastille and was elected to the National Convention (which aimed at giving France a new political constitution) and in the proces of Louis XVI he voted for the death of the king.

Milhaud took an active part in the conspiracy leading up to 18 brumaire which was the day of the coup d'état by which General Napoleon Bonaparte overthrew the French Directory.

[1] He continued to lead his units in 1810, winning fame for crushing a gang of guerrillas led by Juan Martín Díez and inflicting a stinging defeat on Joaquín Blake at Baza.

In July 1811, as part of Marshal Soult's Army of the South, Milhaud served at the head of 1,595 Dragoons in General Sebastiani's IV Corps.

He fought, on October 10, 1813, in the plain of Zeitz, one of the best fights of cavalry mentioned in French military annals, and in which he completely destroyed regiments of Austrian Latour and Hohenzollern Dragoons, as well as the Kaiser Chevau-légers.

During Napoleon's retreat to the borders of France, Milhaud successfully prevented an allied attempt to cut off the French escape at Eckartsberga and took part in the Battle of Hanau.

Milhaud remained a staunch supporter of Napoleon and during the Hundred Days, he was one of the first to rally to the emperor, and in the Waterloo campaign he commanded the IV Cavalry Corps.

Two days later at the Battle of Waterloo 18 June his divisions took part in the great general cavalry assault on the allied centre, a plan he had opposed but had to execute.