Trafalgar and Austerlitz

In 1805 Britain, Austria and Russia formed the Third Coalition against Napoleon. Two battles that year shaped the next decade. At sea, on 21 October 1805, Admiral Nelson's British fleet defeated a combined French and Spanish fleet off Cape Trafalgar in southern Spain. Nelson was killed, but the victory ended any realistic prospect of a French invasion of Britain and confirmed British naval dominance.

On land, Napoleon had already forced an Austrian army to surrender at Ulm, and on 2 December 1805, exactly a year after his coronation, he defeated Austrian and Russian forces at Austerlitz, in what is now the Czech Republic. Austria made peace at Pressburg. The contrast is crucial: Napoleon could dominate the European continent, but Britain controlled the oceans, so neither could easily defeat the other, a stalemate that shaped Napoleon's later economic war.