Kingdom of the Two Sicilies proclaimed under Ferdinand I

Background. Ferdinand had been King of Naples as Ferdinand IV and King of Sicily as Ferdinand III since 1759. He was deposed twice from the Neapolitan throne: first by the revolutionary Parthenopean Republic for six months in 1799, and again by a French invasion in 1806. After the fall of Napoleon, Joachim Murat was dethroned in the Neapolitan War of 1815, and Ferdinand returned to Naples. The Treaty of Casalanza restored him to the throne of Naples, and Sicily, where the constitution of 1812 had virtually disempowered him, was returned to him. This restoration set the stage for the merger of the two kingdoms.

Formation of the Kingdom. The Kingdom of the Two Sicilies was formed by merging the Kingdom of Sicily with the Kingdom of Naples. Both entities were historically named after Sicily, leading to the collective designation "Two Sicilies." The new state became the largest sovereign state in Italy by population and area before unification, covering virtually all of the peninsula south of the Papal States.

Constitutional Character. Ferdinand abolished the Sicilian constitution in violation of his oath, proclaiming the union on 12 December 1816. For the next four years, he reigned as an absolute monarch, granting no constitutional reforms. Political activity was suppressed, and secret societies such as the Carbonari were outlawed in 1816, leading to repression of liberal movements.