From August, he served in Charles Louis Dieudonné Grandjean's division. By early November he transferred again to lead the 2nd Brigade of Maurice Mathieu's division in Marshal Bon-Adrien Jeannot de Moncey's III Corps. On 23 November, Mathieu's division fought in the French victory at the Battle of Tudela. From 19 December 1808 to 20 February 1809, the III Corps participated in the Second Siege of Zaragoza. In this bloodbath, 18,000 Spaniards died of battle injuries or sickness. French losses were also staggering, with 4,000 killed in battle plus an additional 6,000 succumbing to disease. The III Corps, now led by Jean-Andoche Junot easily overran the Ebro valley after the fall of Saragossa. However, Spanish guerillas and regulars were soon active again. As war with Austria threatened, Napoleon withdrew large forces from Spain, leaving Junot only 15,000 troops to occupy the province of Aragon.