when the plotters failed to seize control of the frontier fortresses. In one incident, Louis-Nicolas Davout's volunteer battalion fired on Dumouriez. While the cavalry and some of the regular infantry might have gone along with the scheme, the artillery and the volunteers, pro-Revolution to the core, refused to follow their general. On 5 April 1793, Dumouriez defected to the Austrians with Duke Louis of Chartres, Jean-Baptiste Cyrus de Valence and other officers. With the plot in ruins, the Austrians resumed hostilities. Condé-sur-l'Escaut occupies a strategic location at the confluence of the Scheldt (Escaut) and Haine Rivers. The Romans recognized this when they founded a town at the site. Subsequent residents fortified the location so that by the end of the Middle Ages, Condé was defended by a stone wall with towers surrounded by a moat. The Spanish first tried to modernize the defenses in 1654, but the town was captured by the French general Henri de la Tour d'Auvergne, Vicomte de Turenne the following year. After the French returned Condé by the Treaty of the Pyrenees in 1659, the Spanish converted the town into a fortress. They built a new bastioned trace around the town, outside the old wall which was kept as an inner line. Originally, the new defenses were constructed of earth, but in 1666, the bastions on the west side were revetted with stone. On the south side, a hornwork was built to protect the old town castle. In case of attack, the defenders could easily flood the ditch with water from the rivers. In April 1676 a French army laid siege to the town. Condé was ceded to France by the Treaty of Nijmegen in 1678. Fortifications expert Sébastien Le Prestre de Vauban greatly improved the defenses on the east side, adding two demi-bastions and a full bastion. He also constructed sluice gates so that the garrison could control the depth of the water in the ditches and flood areas on the east side. Outside the fortress, Vauban built five square redoubts in order to keep an attacker away from the main defenses as long as possible. The fortress was undisturbed during the wars of King Louis XIV. The engineer Pierre du Buat made some alterations to Condé in the 1770s. Siege A 6,000-strong Coalition division led by Duke Ferdinand Frederick Augustus of Württemberg invested Condé-sur-l'Escaut on 8 April 1793. The Austrian portion of Württemberg's force