It was founded after the Bourbon Ferdinand IV & III of Naples and Sicily sided with the Third Coalition against Napoleon, and was in return ousted from his kingdom by a French invasion.

[1] In the lead up to the War of the Third Coalition in 1805, Maria Carolina assured the French ambassador to Naples, Charles-Jean-Marie Alquier, that her country would remain neutral during the conflict.

However, the Neapolitan sovereigns were playing a double game: a secret treaty had been signed on 10 September in Naples with the Russian emissary Alexander Tatishchev [ru].

[2] On 14 October, in accordance with the Franco-Neapolitan treaty, French troops commanded by General Laurent de Gouvion Saint-Cyr began their withdrawal, but in the weeks that followed a Russian and British expeditionary force landed in Naples.

[3] On 27 December, the day after the signing of the Treaty of Pressburg between France and Austria, Napoleon declared at the Schönbrunn Palace: "The dynasty of Naples has ceased to reign.

Napoleon intended to prolong the effect of the Battle of Austerlitz to drive the Austrian and Russian troops out of Italy while seizing the Kingdom of Naples, the last possession of the House of Bourbon in the peninsula.

The region was not pacified until the end of the summer, after the intervention of Masséna's troops, while Gaeta, defended by Prince Louis of Hesse-Philippsthal, who refused to obey orders to surrender, fell after a siege of almost five months.

This was announced to him by a delegation from the Sénat conservateur, sent to Naples by Napoleon and composed of Pierre-Louis Roederer, Catherine-Dominique de Pérignon and Pierre Marie Barthélemy Ferino, who were received by Joseph on 11 May.

In his correspondence with his brother, Napoleon indicated to him that his sovereignty would only assured after the arrival of the senators, a way of showing that his kingdom was directly integrated into the French system.

In the modernising spirit of the French Revolution, King Joseph Napoleon implemented a programme of sweeping reforms to the organisation and structure of the ancient feudal kingdom.

The Neapolitan nobility in its majority welcomed the change of regime with benevolence, while expecting guarantees and the consolidation of the new authority, as the local elites were tired of the authoritarianism of former queen Marie Caroline of Austria.

Under Joseph, the monarchical and authoritarian framework was preserved, but in the context of an active policy of administrative, judicial, military, financial, social, educational and cultural reforms.

Upon becoming King of Naples, Joseph Bonaparte launched a series of reforms designed to ensure the shift of state structures towards rationality, order and efficiency, notably with the creation of:[5] The territorial organization was similar to that of France: it saw the creation of thirteen provinces, headed by an intendant, and forty-two districts, headed by a sub-intendant.

King Joseph, however, went further by promulgating the Law of 8 December 1806, determining that the 2,520 communes of the kingdom would be grouped into 495 "governments", even more structuring than the French cantons.

[9] For daily transactions and investments, in addition to structural savings and a reduction in the number of agents, the modernization of taxation and administration was undertaken from 1806, with the establishment of new contributions, the grouping of taxes, an increase in customs tariffs, the operation of the lottery and stamp duty, the improvement of the land registry, the abolition of leases granted to barons, and the creation of the Public Debt Ledger.

Although the political dominance of lords and the clergy had disappeared decades earlier, their economic power and influence over people's minds remained strong.

In most communes, peasants continued to pay fees in kind or in cash for various aspects of rural life: land sales, seeds, water, manure, amounting to nearly 180 different levies.

[5] Resistance to these measures was strong, but Joseph's initiatives were continued under the reign of Joachim Murat and upheld by the restored Bourbons, who made few changes to the decisions taken during the Napoleonic decade.

[15] Most monastic orders were also suppressed and their funds transferred to the royal treasury; the Benedictines and Jesuits were dissolved, but Joseph preserved the Franciscans.

Joseph did not take into account the negative image that the French had of the local nobility, despised due its plethora of 163 princes and 279 dukes, who often had no means to maintain their rank.

"[8] Joseph became King of Spain, and the crown of Naples was offered to Marshal Joachim Murat, husband of Napoleon's sister Caroline Bonaparte.

His experience allowed him to accomplish this task; to do so, Murat abolished the military commissions, granted amnesty to deserters, pardoned dozens of convicts sentenced to death and recalled the émigrés.

The Emperor demanded money, troops, and imposed on Naples the opening of its borders to French products and a strict enforcement of the Continental Blockade.

Roederer, the former Minister of Finance, had left with Joseph, civil servants and soldiers had not been paid in months and the country was plagued by brigandage.

At the same time, Caroline seconded her husband, establishing a boarding school to educate young women from Neapolitan high society.

[20] Murat's successes as king led him to seek increasing autonomy from Napoleon, in order to reign in complete independence from the French Empire.

[21] On 17 January, Murat issued a proclamation to the people of Italy in which he announced the side he had just taken and the goal he was pursuing: "just reasons have led us to seek an alliance with the Coalition against the Emperor of the French and we have had the good fortune of being welcomed".

[19] Marching his troops north, Murat's Neapolitans joined the Austrians against Napoleon's stepson, Eugène de Beauharnais, Viceroy of the Kingdom of Italy.

Upon Napoleon's return from Elba in 1815, Murat struck out from Rimini at the Austrian forces in northern Italy in what he considered a pre-emptive attack.