Siege of Ath (1697)

The siege of Ath (15 May 1697 – 5 June 1697) was a siege of the Nine Years' War. The French stockpiled 266,000 French pounds of gunpowder for the siege and used less than half of it. Consumption of other material amounted to 34,000 pounds of lead, 27,050 cannonballs, 3,400 mortar bombs, 950 grenades and 12,000 sandbags. The financial costs were 89,250 French livres. After the garrison's capitulation, 6,000 peasant workers filled up the trenches. Of the 62 French engineers present, two were killed and seven seriously wounded. This demonstration of French military potency, combined with the successful storming of Barcelona the same year, convinced the Allies to come to terms with France in the treaty of Ryswick, thus ending the war.

The siege was hailed by contemporaries as Vauban's masterpiece and the most efficient siege ever conducted, owing to its speed, low costs and the modernity of the eight-bastion fortress, which had been designed by Vauban himself 25 years earlier.