May, an Austrian army of 40,000 under Count Claude Florimond de Mercy crossed the Alps and threatened to close in on the French army's rear by a flanking maneuver. Villars responded by retreating from Mantua and attempted without success to interrupt the Austrian army's crossing of the Po River. Villars, frustrated by Charles Emmanuel's delaying tactics, quit the army on May 27. He fell ill on the way back to France and died in Turin on June 17. Mercy's forces made repeated attempts to cross the Parma River in June, but it was not until late in that month that they were able to cross the river and approach the city of Parma, where the allied forces, now under the command of French marshals de Broglie and Coigny, were entrenched. In a Battle of Colorno before and in a bloody battle near the village of Crocetta on June 29, the Austrians were beaten back, Mercy was killed, and Frederick of Württemberg, his second, was wounded. Charles Emmanuel returned the next day to retake command, and resumed his delaying tactics by failing to immediately pursue the retreating Austrians. The Austrians retreated to the Po, where they were reinforced by additional troops and placed under the command of Field Marshal Königsegg. After two months of inaction, during which the armies faced each other across the Secchia River, Königsegg on September 15 took advantage of lax security and executed a raid on Coigny's headquarters at Quistello, very nearly capturing Coigny and taking among other prizes Charles Emmanuel's china. Two days later the French withdrew to a position near Guastalla in response to Austrian maneuvers, but one detachment of nearly 3,000 men was surrounded and captured by the advancing Austrians. On September 19, Königsegg attacked the allied position at Guastalla, and in another bloody encounter, was beaten back, losing among others Frederick of Württemberg. Königsegg retreated across the Po, adopting a defensive position between the Po and the Oglio while Charles Emmanuel again did not capitalize on his victory. When he finally withdrew most of the allied army to Cremona, the Austrians advanced on the north bank of the Po as far as the Adda before both armies entered winter quarters in December 1734. In southern Italy, the Austrians, choosing a strategy of defending a large number of fortresses, were soundly defeated. Don Carlos assembled an army composed primarily of Spaniards, but also including