Napoleon's first defeat in his attempt to take over europe was the peninsula war. the battle of waterloo. the battle of trafalgar. the battle of moscow.

The naval battle of Trafalgar off the coast of Spain was Napolean's first military defeat. The English navy commanded by Lord Nelson defeated the French and Spanish fleets. This battle gave England control of the seas and garunteed that the French could not invade England. The battle was fought in October 1805.

a is correct

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