Invasion of Naples (1806)

The invasion of Naples was a military campaign of the War of the Third Coalition in 1806. It began when a French army led by Marshal André Masséna marched from Northern Italy into the Kingdom of Naples, an ally of the Coalition against France ruled by King Ferdinand IV. The Neapolitan army was defeated at Campo Tenese and rapidly disintegrated. The invasion was eventually successful despite some setbacks, including the prolonged Siege of Gaeta, the British victory at Maida, and a stubborn guerrilla war by local peasants against the French. Total success eluded the French because Ferdinand withdrew to his domain in Sicily, where he was protected by the Royal Navy and a British Army garrison. In 1806, Emperor Napoleon appointed his brother Joseph Bonaparte to rule over Southern Italy as king.

The proximate cause of the invasion was Ferdinand's double-crossing of Napoleon. Wanting to keep things quiet in southern Italy, Napoleon and Ferdinand signed a convention that specified that the French would evacuate Apulia. In return, the Kingdom of Naples would stay neutral in the impending War of the Third Coalition. When the French occupying force marched away, Ferdinand admitted British and Russian armies into his kingdom. In December 1805, Napoleon's armies crushed the armies of Austria and Russia. When the Russian force in Naples was recalled, the British expedition withdrew, exposing Ferdinand's kingdom to French retribution.