in the rebellion were tried and sentenced. Cavour moved to challenge republican unification efforts by Garibaldi by organizing popular revolts in the Papal States and used these revolts as a pretext to invade the country, even though the invasion angered the Roman Catholics, whom he told that the invasion was an effort to protect the Roman Catholic Church from the anti-clerical secularist nationalist republicans of Garibaldi. Only a small portion of the Papal States around Rome remained in the control of Pope Pius IX. Despite their differences, Cavour agreed to include Garibaldi's Southern Italy allowing it to join the union with the Kingdom of Sardinia in 1860. Subsequently, the Parliament declared the creation of the Kingdom of Italy on 18 February 1861 (officially proclaiming it on 17 March 1861) composed of both Northern Italy and Southern Italy. King Victor Emmanuel II of Sardinia was then declared King of Italy, though he did not renumber himself with the assumption of the new title. This title had been out of use since the abdication of Napoleon I of France on 6 April 1814. Following the unification of most of Italy, tensions between the royalists and republicans erupted. In April 1861, Garibaldi entered the Italian parliament and challenged Cavour's leadership, accusing him of dividing Italy, and threatened a civil war between the Kingdom in the North and his forces in the South. On 6 June 1861, the Kingdom's strongman Cavour died. During the ensuing political instability, Garibaldi and the republicans became increasingly revolutionary in tone. Garibaldi's arrest in 1862 set off worldwide controversy. In 1866, Otto von Bismarck, Minister President of Prussia, offered Victor Emmanuel II an alliance with the Kingdom of Prussia in the Austro-Prussian War. In exchange, Prussia would allow Italy to annex Austria-controlled Veneto. King Emmanuel agreed to the alliance, and the Third Italian War of Independence began. Italy fared poorly in the war with a badly-organized military against Austria, but Prussia's victory allowed Italy to annex Veneto. At this point, one major obstacle to Italian unity remained: Rome. In 1870, Prussia went to war with France, igniting the Franco-Prussian War. To keep the large Prussian Army at bay, France abandoned its positions in Rome – which protected the remnants of the Papal States and Pius IX – to fight the Prussians. Italy benefited from Prussia's victory against France by taking over the Papal States from French authority. The Kingdom