Francesco della Rovere (Sixtus IV) elected Pope

Pope Sixtus IV (July 21, 1414 – August 12, 1484), born Francesco della Rovere, was Pope from 1471 to 1484.

He founded the Sistine Chapel where the team of artists he brought together and introduced the Early Renaissance to Rome with the first masterpiece of the city's new artistic age.

Francesco was born to a modest family near Savona, Liguria, Italy: the son of Leonardo della Rovere and Luchina Monteleoni. The precise town is variously stated to be Albisola or, more often, Celle Ligure, a town near Savona in the Republic of Genoa.
As a young man he joined the Franciscan Order, an unlikely choice for a political career, and his intellectual qualities were revealed while he was studying philosophy and theology at the University of Pavia. He went on to lecture at many eminent Italian universities.
At the age of 50 he was elected Minister General of the Franciscan order in 1464. In 1467, he was made a Cardinal by Pope Paul II (1464–1471).

Papal election
Main article: Papal conclave, 1471
Upon election to pope he adopted the name Sixtus - a name that had not been used since the 5th century. One of his first acts was to declare a renewed crusade against the Ottoman Turks in Smyrna. Fund-raising for the crusade was more successful than the half-hearted attempts to storm Smyrna, with little to show in return. Some fruitless attempts were made in unification with the Greek Church. For the remainder of his pontificate he turned to temporal issues and dynastic considerations. Sixtus continued the dispute with Louis XI of France (1461–1483), who upheld the Pragmatic Sanction of Bourges (1438), according to which papal decrees needed royal assent before they could be promulgated in France. This was a cornerstone of the privileges claimed for the Gallican Church and could never be shifted as long as Louis XI maneuvered to replace Ferdinand I of Naples with a French prince, thus being in conflict with the papacy, which as a princely strategist could not permit it.

Like a number of Popes, Sixtus IV adhered to the system of nepotism. In the fresco by Melozzo da Forlì he is accompanied by his Della Rovere and Riario nephews, not all of whom were made cardinals: the protonotary apostolic Raffaele Riario (on his right), the future Pope Julius II (1503–1513) standing before him, and Girolamo Riario and Giovanni della Rovere behind the kneeling Platina, author of the first humanist history of the Popes. His nephew Pietro Riario also benefited of his nepotism, becoming one of the richest men in Rome and being entrusted of Sixtus IV's foreign policy, but died prematurely in 1474, his role passing to Giuliano della Rovere.
The secular fortunes of the Della Rovere began when Sixtus invested his nephew Giovanni with the signoria of Senigallia and arranged his marriage to the daughter of Federico III da Montefeltro, duke of Urbino; from the union came a line of Della Rovere dukes of Urbino that lasted until the line expired, in 1631.
In his territorial aggrandizement of the Papal States Sixtus IV's niece's son Cardinal Raffaele Riario, for whom the Palazzo della Cancelleria was constructed, was a leader in the 1478 failed "Pazzi conspiracy" to assassinate both Lorenzo de' Medici and his brother and replace them in Florence with Sixtus IV's other nephew, Girolamo Riario. Francesco Salviati, archbishop of Pisa and a main organizer of the plot, was hanged on the walls of the Florentine Palazzo della Signoria. To this Sixtus IV replied with an interdict and two years' of war with Florence. He also encouraged the Venetians to attack Ferrara, which he wished to obtain for another nephew. The angered Italian princes allied to force Sixtus IV to make peace, to his great annoyance.

Foreign policy
As a temporal prince who constructed stout fortresses in the Papal States, Sixtus IV committed himself to Venice's aggression against Ercole I d'Este, Duke of Ferrara, inciting the Venetians to attack in 1482 in the so-called War of Ferrara. Their combined assault was opposed by an alliance of the Sforzas of Milan, the Medicis of Florence along with the King of Naples, normally a hereditary ally and champion of the Papacy. For refusing to desist from the very hostilities that he himself had instigated (and for being a dangerous rival to Della Rovere dynastic ambitions in the Marche), Sixtus IV placed Venice under interdict in 1483.
On November 1, 1478, Pope Sixtus IV published the Papal bull Exigit Sinceras Devotionis Affectus, through which the Spanish Inquisition was established in the Kingdom of Castile. Sixtus IV consented under political pressure from Ferdinand of Aragon, who threatened to withhold military support from his kingdom of Sicily. Nevertheless, Sixtus IV quarrelled over protocol and prerogatives of jurisdiction, was unhappy with the excesses of the Inquisition and took measures to condemn the most flagrant abuses in 1482.
In ecclesiastical affairs, Sixtus IV instituted the feast (December 8) of the Immaculate Conception of the Virgin Mary. He formally annulled (1478) the confusedly reformist decrees of the Council of Constance.

The two papal bulls issued by Pope Nicholas V, "Dum Diveras" (1452) and "Romanus Pontix" (1455), had effectively given the Portuguese the rights to acquire slaves along the African coast by force or trade. These concessions were confirmed by Sixtus in his own bull, "Aeterni regis" (21 June 1481). Arguably the "ideology of conquest" expounded in these texts became the means by which commerce and conversion were facilitated. Sixtus's earlier threats in "Regimini Gregis" (1476) to excommunicate all captains or pirates who enslaved Christians could have been intended to emphasise the need to convert the natives of the Canary Islands and Guinea and establish a clear difference in status between those who had converted and those who resisted. The ecclesiastical penalties were directed towards those who were enslaving the recent converts.

Sixtus IV has been accused of having had male lovers. The basis of this being the diary records of Stefano Infessura who recorded documented episodes, but also unsubstantiated rumours. He was accused of awarding benefices and bishoprics in return for sexual favours, and nominated a number of young men as cardinals, some of whom were celebrated for their looks. While it is indisputable that Sixtus favoured his relatives in the hope of having faithful executors of policy; there is less evidence of direct corruption or favouritism. The exception may perhaps be Giovanni Sclafenato, who was created a cardinal according to the papal epitaph on his tomb for "ingenuousness, loyalty and his others gifts of soul and body". The English theologian John Bale attributed to Sixtus "the authorisation to practice sodomy during periods of warm weather". However, such accusations by Protestant polemicists can be dismissed as attempts at anti-Catholic propaganda.

As a civic patron in Rome, even the anti-papal chronicler Stefano Infessura agreed that Sixtus IV should be admired. The dedicatory inscription in the fresco by Melozzo da Forlì in the Vatican Palace records: "You gave your city temples, streets, squares, fortifications, bridges and restored the Acqua Vergine as far as the Trevi..." In addition to restoring the aqueduct that provided Rome an alternative to the river water that had made the city famously unhealthy, he restored or rebuilt over 30 of Rome's dilapidated churches, among them San Vitale (1475) and Santa Maria del Popolo, and added seven new ones. The Sistine Chapel was sponsored by Sixtus IV, as was the Ponte Sisto, the Sistine Bridge – the first new bridge across the Tiber since antiquity – and the building of Via Sistina (later named Borgo Sant'Angelo), a road leading from Castel Sant'Angelo to Saint Peter. All this was done to facilitate the integration of the Vatican Hill and Borgo with the heart of old Rome. This was part of a broader scheme of urbanization carried out under Sixtus IV, who swept the long-established markets from the Campidoglio in 1477 and decreed in a bull of 1480 the widening of streets and the first post-Roman paving, the removal of porticoes and other post-classical impediments to free public passage.

At the beginning of his papacy in 1471, Sixtus IV donated several historically important Roman sculptures that founded a papal collection of art that would eventually develop into the collections of the Capitoline Museums. He also refounded, enriched and enlarged the Vatican Library. He had Regiomontanus attempt the first sanctioned reorganization of the Julian calendar and increased the size and prestige of the papal chapel choir, bringing singers and some prominent composers (Gaspar van Weerbeke, Marbrianus de Orto, and Bertrandus Vaqueras) to Rome from the North.
In addition to being a patron of the arts, Sixtus IV was a patron of the sciences. Before becoming Pope, spent time at the then very liberal and cosmopolitan University of Padua, which maintained considerable independence from the Church and had a very international character. As pope, he issued a papal bull allowing local bishops to give the bodies of executed criminals and unidentified corpses to physicians and artists for dissection. It was this access to corpses which allowed the anatomist Vesalius along with Titian's pupil Jan Stephen van Calcar to complete the revolutionary medical/anatomical text De humani corporis fabrica.

His bronze funerary monument, now in the basement Treasury of St. Peter's Basilica, like a giant casket of goldsmith's work, is by Antonio Pollaiuolo. The top of the casket is a lifelike depiction of the pope lying in state. Around the sides are bas relief panels, depicting with allegorical female figures the arts and sciences (Grammar, Rhetoric, Arithmetic, Geometry, Music, Painting, Astronomy, Philosophy, and Theology). Each figure incorporates the oak tree ("rovere" in Italian) symbol of Sixtus IV. The overall program of these panels, their beauty, complex symbolism, classical references, and arrangement relative to each other is one of the most compelling and comprehesive illustrations of the Renaissance worldview.

Born near Abisola, 21 July, 1414; died 12 Aug., 1484. His parents were poor, and while still a child he was destined for the Franciscan order. Later he studied philosophy and theology with great success at the University of Pavia, and lectured at Padua, Bologna, Pavia, Siena, and Florence, having amongst other eminent disciples the famous Cardinal Bessarion. After filling the post of procurator of his order in Rome and Provincial of Liguria, he was in 1467 created Cardinal of S. Pietro in Vincoli by Paul II. Whatever leisure he now had was devoted to theology, and in 1470 he published a treatise on the Precious blood and a work on the Immaculate Conception, in which latter he endeavoured to prove that Aquinas and Scotus, though differing in words, were really of one mind upon the question. The conclave which assembled on the death of Paul II elected him pope, and he ascended the chair of St. Peter as Sixtus IV.

His first thought was the prosecution of the war against the Turks, and legates were appointed for France, Spain, Germany, Hungary, and Poland, with the hope of enkindling enthusiasm in these countries. The crusade, however, achieved little beyond the bringing back to Rome of twenty-five Turkish prisoners, who were paraded in triumph through the streets of the city. Sixtus continued the policy of his predecessor Paul II with regard to France, and denounced Louis XI for insisting on the royal consent being given before papal decrees could be published in his kingdom. He also made an effort like his predecessor for the reunion of the Russian Church with Rome, but his negotiations were without result. He now turned his attention almost exclusively to Italian politics, and fell more and more under his dominating passion of nepotism, heaping riches and favours on his unworthy relations. In 1478 took place the famous conspiracy of the Pazzi, planned by the pope's nephew — Cardinal Rafael Riario — to overthrow the Medici and bring Florence under the Riarii. The pope was cognizant of the plot, though probably not of the intention to assassinate, and even had Florence under interdict because it rose in fury against the conspirators and brutal murderers of Giuliano de' Medici. He now entered upon a two years' war with Florence, and encouraged the Venetians to attack Ferrara, which he wished to obtain for his nephew Girolamo Riario. Ercole d'Este, attacked by Venice, found allies in almost every Italian state, and Ludovico Sforza, upon whom the pope relied for support, did nothing to help him. The allied princes forced Sixtus to make peace, and the chagrin which this caused him is said to have hastened his death.

Henceforth, until the Reformation, the secular interests of the papacy were of paramount importance. The attitude of Sixtus towards the conspiracy of the Pazzi, his wars and treachery, his promotion to the highest offices in the Church of such men as Pietro and Girolamo are blots upon his career. Nevertheless, there is a praiseworthy side to his pontificate. He took measures to suppress abuses in the Inquisition, vigorously opposed the Waldenses, and annulled the decrees of the Council of Constance. He was a patron of arts and letters, building the famous Sistine Chapel, the Sistine Bridge across the Tiber, and becoming the second founder of the Vatican Library. Under him Rome once more became habitable, and he did much to improve the sanitary conditions of the city. He brought down water from the Quirinal to the Fountain of Trevi, and began a transformation of the city which death alone hindered him from completing. In his private life Sixtus IV was blameless. The gross accusations brought against him by his enemy Infessura have no foundation; his worst vice was nepotism, and his greatest misfortune was that he was destined to be placed at the head of the States of the Church at a time when Italy was emerging from the era of the republics, and territorial princes like the pope were forced to do battle with the great despots.