The son of a legal officer at the bailliage of Chartres, François Séverin Marceau enlisted at sixteen and had risen to sergeant by 1789. He served in the defence of Verdun in 1792 and was chosen to carry the terms of capitulation to the Prussian camp. Although the surrender subsequently became the subject of investigations and prosecutions, Marceau, who had opposed capitulation, escaped censure.
Sent to the west in 1793, he rose rapidly, becoming general of brigade at twenty-four and general of division later that year. In November he was given temporary command of the Army of the West, on Kléber's recommendation, pending the arrival of a permanent commander. He commanded during the Republican victories at Le Mans and Savenay. The defeat at Le Mans on 12 and 13 December was followed by extensive killings of Vendéen combatants and civilians; Marceau and Kléber attempted to protect prisoners and restrain at least some of the violence, although they were unable to prevent the massacre.
Marceau subsequently served with the Army of Sambre-et-Meuse and occupied Koblenz following its surrender on 23 October 1794. While covering Jourdan's retreat in September 1796, he was mortally wounded near Höchstenbach on 19 September and died at Altenkirchen two days later, aged twenty-seven.
