Unable to land in England, Napoleon closed the continent to its trade: every ship coming from the British Isles was seized, every English good confiscated. The blockade, extended by the Milan, Trianon and Fontainebleau decrees, ruined French ports as much as it hurt London and made smuggling universal. It drove the annexation of Holland, the Spanish war and the rupture with Russia.

A war that cannot be won at sea

Trafalgar had removed any possibility of invasion; London replied in May 1806 by declaring a blockade of the coast from the Elbe to Brest. Napoleon turned the weapon round: since England lived by its trade, the continent would be closed to it. The decree was signed in Berlin, in a Prussian capital occupied for the past fortnight.

The text

The British Isles were declared in a state of blockade; all trade and correspondence with them were forbidden; every English subject found in occupied territory became a prisoner of war; all English goods or goods from its colonies were lawful prize. The Milan decree of December 1807 added that any neutral ship having touched an English port was deemed denationalised.

London retaliated with the Orders in Council, which obliged neutrals to call at a British port: the United States, caught between the two systems, decreed an embargo and then went to war with England in 1812.

What the blockade cost the Empire

The Atlantic ports — Bordeaux, Nantes, Marseille — collapsed, while the textile industry of the north and Alsace profited from a protected continental market. Smuggling became massive: the licence system created in 1809 amounted to selling exemptions, and the Trianon tariffs to taxing what was supposedly banned.

Above all, the blockade imposed its political logic: every coastline had to be controlled. Hence the annexation of Holland, the occupation of the Hanseatic cities, the Spanish war and, in 1812, the Russian campaign. The economic weapon dictated strategy and ended by wearing the Empire out.