The Battle of Aspern-Essling (21 May 1809) punctured Napoleon’s aura of invincibility. Although no rout, it represented his first defeat in a major engagement, and demonstrated the growing shortcomings of the formidable Grande Armée. Swelled by raw recruits and non-French contingents, it was no longer the perfect instrument of Napoleon’s vision. Earlier, Napoleon had decisively defeated the initial Austrian invasion of Bavaria in a series of engagements around Ratisbon, then rapidly proceeding to take Vienna. Meanwhile, the French in the Adige fared poorly in pitched battles but managed to repulse the Austrian offensive. After his reverse, Napoleon regrouped and won a hard-fought victory at Wagram (5–6 Juy 1809), forcing the Austrians to sue for peace. Napoleon imposed harsh terms on Austria at the Treaty of Schonbrunn, but had now proved been mortal. His new tactical fallibility would be eclipsed by gross strategic miscalculation in the invasion of Russia, and the ensuing catastrophic retreat.
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