Which naval battle in 1805 prevented Napoleon's invasion of Britain?

Which naval battle in 1805 prevented Napoleon's invasion of Britain? The Battle of Trafalgar prevented Napoleon from achieving command of the sea for an invasion of Britain.

Fought off Spain's Cape Trafalgar on 21 October 1805, the battle pitted Vice Admiral Horatio Nelson's British fleet against a combined French-Spanish force commanded by Pierre-Charles Villeneuve. Nelson's unconventional attack split the allied line and destroyed or captured many enemy ships, though Nelson himself was fatally wounded.

The victory preserved Britain's naval supremacy and made a cross-Channel invasion effectively impossible. Napoleon had assembled the Grande Armée at Boulogne and needed control of the Channel to move it safely across. After the naval plan collapsed, he abandoned the invasion preparations and redirected the army eastward, beginning the Ulm campaign against Austria.

A useful nuance is that the invasion had already been postponed and was being abandoned before Trafalgar was fought. The battle nevertheless permanently removed any realistic prospect of Napoleon forcing Britain to submit by invasion and guaranteed British control of the surrounding seas.