In September, 1567, the second religious war broke out.
It was short, and not decisive for either party.

At the outset of the campaign, success was with the Protestants; forty towns, Orleans, Montereau, Lagny, Montauban, Castres, Montpellier, Uzes, &c., opened their gates to them or fell into their hands.
They were within an ace of surprising the king at Monceaux, and he never forgot, says Montluc, that "the Protestants had made him do the stretch from Meaux to Paris at something more than a walk." It was around Paris that Conde concentrated all the efforts of the campaign.

He had posted himself at St.Denis with a small army of four thousand foot and two thousand horse.

The Constable de Montmorency commanded the royal army, having a strength of sixteen thousand foot and three thousand horse.
Attempts were made to open negotiations; but the constable broke them off brusquely, roaring out that the king would never tolerate two religions.
On the 10th of November, 1567, the battle began at St.Denis, and was fought with alternations of partial success and reverse, which spread joy and sadness through the two hosts in turn; but in resisting a charge of cavalry, led to victory by Conde, the constable fell with and under his horse; a Scot called out to him to surrender; for sole response, the aged warrior, "abandoned by his men, but not by his manhood," says D'Aubigne, smashed the Scot's jaw with the pommel of his broken sword; and at the same moment he fell mortally wounded by a shot through the body.

His death left the victory uncertain and the royal army disorganized.