Camillo Paolo Filippo Giulio Benso, Count of Cavour, of Isolabella and of Leri (August 10, 1810 – June 6, 1861) was a leading figure in the movement toward Italian unification. He was the founder of the original Italian Liberal Party and Prime Minister of the Kingdom of Piedmont-Sardinia, a position he maintained (except for a six-month resignation) throughout the Second Italian War of Independence and Garibaldi's campaigns to unite Italy. Cavour died only three months after the declaration of a united Kingdom of Italy, and thus did not live to see Venetia or Rome included in the kingdom.

Cavour, as he is usually called, put forth several economic reforms in his native region of Piedmont in his earlier years, and founded the political newspaper Il Risorgimento. After being elected to the Chamber of Deputies, he quickly rose in rank through the Piedmontese government, coming to dominate the Chamber of Deputies through a union of left-center and right-center politicians. After a large rail system expansion program, Cavour became prime minister in 1852. As prime minister, Cavour successfully negotiated Piedmont's way through the Crimean War, Second Italian War of Independence, and Garibaldi's expeditions, managing to maneuver Piedmont diplomatically to become a new great power in Europe, controlling a nearly united Italy that was five times as large as Piedmont had been before he came to power. He is generally viewed as the mastermind of the unification of Italy. He founded a nationalist newspaper called Risorgimento.

Camillo Benso was born in Turin during Napoleonic rule, into a family that had gained a fair amount of land during the French occupation. He was the second of two sons of Michele Giuseppe Francesco Antonio Benso, 5th Marquess of Cavour and Count of Isolabella, Baron of the French Empire (1781 – 1850) and his wife Adélaïde (Adèle) Suzanne, Marchioness of Sellon (1780 – 1846), herself of French origin. Cavour was sent to the Turin Military Academy when he was only ten years old. Cavour frequently ran afoul of the authorities in the academy, as he was too headstrong to deal with the rigid military discipline. He was once forced to live three days on bread and water because he had been caught with books that the academy had banned. He was found to be apt at the mathematical disciplines, and was therefore enlisted in the Engineer Corps in the Piedmontese-Sardinian army in 1827. While in the army, he studied the English language as well as the works of Jeremy Bentham and Benjamin Constant, developing liberal tendencies which made him suspect to police forces at the time. He resigned his commission in the army in November 1831, both because of boredom with military life and because of his dislike of the reactionary policies of the new ruler of Piedmont, Charles Albert.

Cavour then spent his time in Switzerland, along with his Protestant relatives in Geneva. He grew acquainted with Calvinist teachings, and for a short while he converted from a form of unorthodox Catholicism, only to go back later. A Reformed pastor, Alexandre Vinet, impressed upon Cavour the need for the separation of church and state, a doctrine Cavour followed for the remainder of his life. He then traveled to Paris where he was impressed by parliamentary debates, especially those of François Guizot and Adolphe Thiers, confirming his devotion to a political career. Afterwards, he left for London, where he was much more disappointed by their politics, though continuing to tour the country, heading to Oxford, Liverpool, Birmingham, Chester, Nottingham, and Manchester. A quicker tour through the Netherlands, Germany, and Switzerland (German part and Lake of Geneva) eventually landed him back in Turin.

Between 1838 and 1842 Cavour began several initiatives in attempts to solve economic problems in his area. Firstly he experimented with different agricultural techniques on his estate, such as the use of sugar beet, and was one of the first Italian landowners to use chemical fertilizers. He also founded the Piedmontese Agricultural Society. Cavour was a heavy supporter of transportation by steam engine, sponsoring the building of many railroads and canals. In his spare time, he again traveled extensively, mostly in France and the UK.

The first apparently "liberal" moved of pope Pius IX spawned a new movement of Italian liberalism, allowing Cavour to enter the political arena, no longer in fear of the police. He then gave a speech in front of numerous journalists in favor of a constitution for Piedmont, which was eventually granted. Cavour, unlike several other political thinkers, was not at first offered a position in the new Chamber of Deputies, as he was still a somewhat suspicious character to many. Cavour never planned for the establishment of a united country, and even later during his Premiership his objective was to expand Piedmont with the annexation of Lombardy and Venetia, rather than a unified Italy. For example, during the conservative period, he gained a reputation as a non-revolutionary progressive. He had trouble publicly speaking as he tended to speak French privately but preferred to attempt speaking in Italian in Parliament. Cavour then lost the next election, while the Piedmontese army was destroyed at the Battle of Novara, leading Charles Albert to abdicate, leaving his son, Victor Emmanuel II in charge.

Cavour was then brought back into Parliament by the voters, where he was much more successful. His knowledge of European markets and modern economy earned him the position as Minister of Agriculture, Commerce and the Navy in 1850. Cavour soon came to dominate the cabinet and united the Right Center and the Left Center in the chamber to show dominance there as well. In 1851, Cavour gained a Cabinet promotion to Minister of Finance by working against his colleague from inside the Cabinet in a somewhat disreputable takeover, though it was to Piedmont's advantage through his many economic reforms. This allowed Cavour to begin his vast railway expansion program, giving Piedmont 800 kilometres of track by the year 1860, one third of the railways in Italy at the time. These moves eventually earned him the title of Prime Minister of Piedmont on 4 November 1852. Cavour was generally liberal and believed in free trade, public right of opinion, and secular rule, but was still an enemy of the republicans and revolutionaries inside Piedmont, attempting to balance their needs. Cavour is criticised for a number of controversial methods he used while prime minister, including excessive use of emergency powers, employing friends, bribing newspapers while suppressing others, and rigging elections, though these things were fairly common for the time. Still, Cavour's career as prime minister can be considered one of the most successful of all time, given that when he took up the post, Piedmont had just suffered a horrible loss to Austria, and when Cavour died, Victor Emmanuel II ruled a state five times as large, now ranking among Europe's great powers. Cavour in fact radically increased the wealth and growth of Piedmont. In twelve years wealth had increased to 725 million liras. Piedmont had 20% of the Italian population but held 27% of the exports. Piedmont, under cavour, was the most powerful state.

In early 1853, the Crimean War broke out, pitting Great Britain, France, and the Ottomans against Russia. The allied powers of Britain and France asked Piedmont to enter the war partially in order to encourage Austria to enter, which they would not do unless they were certain that Piedmontese troops were not available to fight in Italy. Cavour, who hoped that support for the western allies would lead to their support for Sardinia's ambitions in Italy, agreed as soon as his colleagues' support would allow, and entered the war on France and Britain's side on January 10, 1855, too late to truly distinguish themselves militarily, yet the entry turned out to be a useful political move for Piedmont's future. Their 18,000 man contingent did manage to earn Piedmont a position at the Peace Congress in Paris.

In January 1858, the Italian Felice Orsini's attempt at murdering Napoleon III paradoxically opened up a new possibility at diplomacy between France and Italy. While in jail awaiting trial, Orsini wrote a publicly published letter to the Emperor of the French, ending with "Remember that, so long as Italy is not independent, the peace of Europe and Your Majesty is but an empty dream... Set my country free, and the blessings of twenty-five million people will follow you everywhere and forever." Orsini would still be executed, but Napoleon III would begin to explore the possibility of joint operation with Piedmont against Austria. Cavour and Napoleon would meet in July 1858 at Plombières-les-Bains, and the two agreed that Piedmont would attempt to enter war by engineering a conflict with the Duchy of Modena, obliging Austria to enter, and France would come to aid Piedmont. Cavour also reluctantly agreed to cede Savoy and Nice to France if aid was given in war. A royal marriage was proposed and carried out between Princess Clotilde and Prince Napoleon to seal the agreement, surprisingly made without Victor Emmanuel's consent. Both France and Piedmont began to prepare for war, but diplomatic support for the war appeared to be diminishing rapidly. Napoleon III was quickly souring on the idea, and Britain, Prussia, and Russia were proposing an international congress, with one point likely to be the disarmament of Piedmont. Piedmont was saved from this situation by Austria's sending an ultimatum on April 23, demanding that Piedmont disarm itself, and casting Austria as an aggressor. France immediately mobilised its army and slowly began to enter Italy, but Piedmont would need to defend itself for a short period. Rainstorms and Austrian indecision under Ferencz Graf Gyulai allowed France time to take position.

The following battles of Magenta and Solferino managed to give the Franco-Piedmontese forces control over Lombardy and a victorious position, though the Austrians remained confident in defending their "fortress quadrilateral" area, with four fortresses in Verona, Legnano, Peschiera, and Mantua. These defenses, the horrors of the Battle of Solferino, the possibility of German entry into the war, and the potential for an overly strong Piedmontese state convinced Napoleon to sign a separate peace with Austria in the Treaty of Villafranca on July 11, 1859, ending the Second Italian War of Independence. Cavour was so infuriated after reading the terms of the treaty that he tendered his resignation to Victor Emmanuel, who was accepting peace due to Piedmont's inability to fight Austria alone. Cavour would quickly regain confidence, as several of the terms, such as the restoration to power of the rulers of Tuscany and Modena, would not actually be carried out. For now, General La Marmora succeeded Cavour's post and insisted on following Villafranca, even sending a letter to Tuscany asking that they restore their Grand Duke. Bettino Ricasoli, virtual dictator of Tuscany at the time, wrote about this appeal to his brother, saying "Tell General La Mormora that I have torn his letter into a thousand pieces." France would continue direct talks with Piedmont on the destiny of the central Italian states, as all of them at the time were ruled by dictators supporting merging with Piedmont, but were restrained from doing so by the treaty, which called for them to return to their old governments.

Cavour had retired to his estate at Leri, closely monitoring events during his short absence from power, but soon became impatient with government proceedings and actively entered politics again, immediately forcing La Marmora to resign due to Cavour's control of the chamber. Victor Emmanuel was very reluctant to assign Cavour to be prime minister, due both to their quarrel over Villafranca and Cavour's success in restricting the king from marrying his mistress after the queen's death. Cavour was however sent for on January 20, 1860 to again take over the government. Cavour immediately negotiated with Napoleon, agreeing to finally cede Savoy and Nice in order to annex Tuscany and Emilia. Plebiscites in Tuscany and Emilia came out as huge majorities in favor of unification, though still with a number of abstentions supporting the old government. Garibaldi was furious at finding that his birthplace, Nice, had become a French city, but Cavour managed to convince most that uniting Italy would make up for these small territorial losses. With this, the first stage of unification was completed, and it would be Garibaldi's turn to bring southern Italy into Piedmont's control.

Garibaldi, still fuming at the loss of his hometown to France, wished to recapture the city, but a popular insurrection in Palermo on April 4, 1860, diverted him from pursuing that cause. Garibaldi requested a brigade from the Piedmontese army to take Sicily from the Bourbon Neapolitans who ruled it at the time, but was immediately refused by Cavour. A band of volunteers was instead brought together, who would come to be known as I Mille, or the Thousand. This small group of redshirts landed at Marsala in Sicily on May 11, later to fight the battles of Calatafimi and Milazzo, consolidating Sicily in Garibaldi's power. Cavour attempted to immediately annex Sicily to the Piedmontese, but Garibaldi and his accomplice Francesco Crispi would not allow it.

Cavour persuaded Victor Emmanuel II to write a letter to Garibaldi requesting that he not invade the mainland; the letter was indeed sent, but Victor Emmanuel secretly wished for Garibaldi to invade, having written another letter asking him to go ahead which was apparently never sent. Cavour realized these efforts were fruitless, and attempted to stir up a liberal revolution in Naples, but the populace was not receptive. Garibaldi invaded the mainland anyway, attempting to reach Naples quickly before Cavour found a way to stop him. On September 7, Garibaldi successfully entered Naples, at that time the largest city in Italy. Southern Italy and Sicily were now under Garibaldi, who ruled with dictatorial powers. Garibaldi also publicly demanded that Cavour be removed from his post as prime minister, alienating him slightly from Victor Emmanuel II. Garibaldi was not willing to stop at this point, however, and planned for an immediate invasion of the Papal States and Rome. Cavour knew that France may declare war if such an invasion happened, and would successfully stop Garibaldi from initiating his attack. Garibaldi had been weakened by the Battle of Volturno, so Cavour quickly invaded the Papal regions of Umbria and the Marche. This linked the territories owned by Piedmont with those taken by Garibaldi, and the king met Garibaldi halfway at Naples, where Garibaldi handed over power of southern Italy and Sicily, uniting Italy. The relationship between Cavour and Garibaldi was always fractious: Cavour likened Garibaldi to "a savage" while Garibaldi memorably called Cavour "a low intriguer".

On March 17, 1861, Victor Emmanuel II became the King of Italy, making Cavour officially prime minister of Italy. Cavour had many stressful topics that all needed consideration, including how to create a national military, which legal institutions should be kept for where, the future of Rome, which most still believed must be capital of a united Italy, and any number of other concerns. Cavour believed that Rome should remain "a free church in a free state", allowed to maintain its independence though forced to give up temporal power. Still Austrian Venetia was also a problem. Cavour recognized that Venice must be an integral part of Italy, but refused to take a stance on how to achieve it, saying "Will the deliverance of Venice come by arms or diplomacy? I do not know. It is the secret of providence." A motion approving of his foreign policy passed by a huge majority, basically only opposed by both left and right-wing extremist groups.

Creating Italy was no easy task, but ruling it proved a worse strain on the Prime Minister. In 1861, at the peak of his career, months of long days coupled with insomnia and constant worry took their toll on Cavour. He fell ill, presumably of malaria, and to make matters worse, insisted upon being bled. His regular doctor would have refused, but he was not available, so Cavour was bled several times until it was nearly impossible to draw any blood from him. He died on June 6 of a stroke, fifty years old. His last words were reportedly "Italy is made. All is safe." This quote was surprisingly optimistic compared to how most Europeans were greeting the unification of Italy, as Napoleon III said upon hearing of Cavour's death, "The driver has fallen from the box; now we must see if the horses will bolt or go back to the stable". Massimo d' Azeglio, the prime minister of Piedmont before Cavour, asked "Who now is going to be the counterweight to Mazzini and Garibaldi? Who now can keep the revolution safe indoors like some domesticated hyena?" Despite these comments, Italy would gain Venice in 1866 through the Austro-Prussian War and Rome in 1870 after the Pope's declaration of papal infallibility and France's defeat at Sedan, completing the unification that few thought could be finished without Cavour.

Today, many Italian cities have important streets or squares named for him, e.g. Trieste, Rome, Florence, Naples. The new Marina Militare aircraft carrier Cavour is also named in his honor. This unit was preceded by the famous battleship Conte di Cavour, which fought both in World War I and World War II.