Spain used up the soldiers needed for Napoleon's other fields of battle, and they had to be replaced by conscripts. Spanish resistance affected Austria, and indicated the potential of national resistance. The provocations of Talleyrand and Britain strengthened the idea that the Austrians could emulate the Spanish. On 10 April 1809, Austria invaded France's ally, Bavaria. The campaign of 1809, however, would not be nearly as long and troublesome for France as the one in Spain and Portugal. Following a short and decisive action in Bavaria, Napoleon opened up the road to the Austrian capital of Vienna for a second time. At Aspern, Napoleon suffered his first serious tactical defeat, along with the death of Jean Lannes, an able Marshal and dear friend of the emperor. The victory at Wagram, however, forced Austria to sue for peace. The Treaty of Schönbrunn, signed on 14 December 1809, resulted in the annexation of the Illyrian Provinces and recognized past French conquests.