Toussaint, however, asserted so much independence that in 1802, Napoleon sent a massive invasion force, under his brother-in-law Charles Leclerc, to increase French control. For a time, Leclerc met with some success; he also brought the eastern part of the island of Hispaniola under the direct control of France in accordance with the terms of the 1795 Treaties of Bâle with Spain. With a large expedition that eventually included 40,000 European troops, and receiving help from white colonists and mulatto forces commanded by Alexandre Pétion, a former lieutenant of Rigaud, the French won several victories after severe fighting. Two of Toussaint's chief lieutenants, Dessalines and Christophe, recognizing their untenable situation, held separate parleys with the invaders and agreed to transfer their allegiance. At this point, Leclerc invited Toussaint to negotiate a settlement. It was a deception; Toussaint was seized and deported to France, where he died of pneumonia while imprisoned at Fort de Joux in the Jura Mountains in April 1803.