The humanist pope who set the standard for Renaissance nepotism
Two members of the della Rovere family made it all the way to the Throne of St. Peter, both of whom utterly transformed Rome and the papacy: Sixtus IV (r. 1471-84) and his nephew, Julius II (r. 1503-13). The family emblem, an oak tree (della rovere: ‘of the oak’), inadvertently captures Sixtus’s ambitions and character during his pontificate. In its sturdy trunk we can see his resolute determination; in its branches, his prolific nepotism; and in its knot, the marriage ties that Sixtus engineered to elevate his family. This final goal, putting his family members into positions of power, attracted much criticism, and would be the defining trait of his reign.
Sixtus, born Francesco della Rovere near Genoa to an obscure family of middling means, was elected pope in his late fifties. The rest of his life was dedicated to two ends: restoring to a shattered and depressed Rome some of its antique glamour and patina and elevating the della Rovere family. He can be said to have achieved both. The urban infrastructure Sixtus and his family erected in Rome remain some of the city’s most handsome, including the Palazzo della Cancelleria and Sixtus’s eponymous Sistine Chapel, which has provided the world with some of humanity’s most enduring and instantly recognisable visual art (though admittedly Sixtus was long dead when Michelangelo began his famous frescoes).
Similarly, Sixtus’s determination to secure for his family the rank of nobility to match that of the peninsula’s most blue-blooded families was a triumph. Sixtus’s nepotism and acute arrangement of marriage alliances lifted the della Rovere from nowhere to become one of Italy’s leading families. But Sixtus’s achievement in this secular realm would have consequences that would reverberate for a generation. When it was recognised the potential for papal power to establish a dynasty, the genie was out of the bottle, and Sixtus’s model would be copied by his successors, most notoriously by Alexander VI Rodrigo Borgia.
The nepotism for which Renaissance popes are famous was initiated in earnest by Sixtus. Previous popes had made at most one or two relatives cardinal; Sixtus made four of his nephews cardinals, and another two della Rovere, who were probably not blood relatives, also joined the cardinalate. There was no precedent for such a blatant promotion of the pope’s family. Sixtus’s familial favouritism was bound to cause problems and did. Sixtus knew that the Papal States, of which he was nominally the ruler, were in reality comprised of cities and territories ruled by aristocratic or noble families that, whilst allied with the pope, were actually near-independent. The further away they were from the city of Rome, the more the local rulers exercised their own independence, particularly to the north in Emilia and Romagna on the Milanese border.
One such town in the region was Imola, which Sixtus arranged to purchase with the intention of making his nephew, ‘the fat, noisy and vulgar’ Girolamo Riario, its ruler, and to consolidate control in the distant north of his realm. Rather prosaically, Sixtus required a loan to buy Imola and applied for one from the Medici bank, ran by Lorenzo de’ Medici, the de facto ruler of Florence. To Sixtus’s misfortune, Lorenzo also wanted Imola, and refused Sixtus his loan. So the pope turned to Medici rivals and fellow Florentine bankers, the Pazzi. Francesco de’ Pazzi, the bank’s branch manager in Rome, saw in this spat an opportunity to overthrow the Medici and hatched a plot with Girolamo Riario and archbishop Francesco Salviati to murder Lorenzo and his brother. They sought the pope’s approval to remove the Medici, which was granted, but only on the proviso ‘there be no killing’.
A killing, of course, is was happened next, and it was horrifically violent. On Easter Sunday 1478, as Lorenzo and his brother stood at the altar of Florence’s Duomo during the Elevation of the Host at High Mass, two assassin priests uncloaked their daggers. Lorenzo was wounded but fled on foot; his unlucky brother Giuliano was slain on the spot, his head struck so hard that his skull was nearly split in two. A furious Sixtus placed Florence under interdict after Salviati was murdered in the bloody fallout from the conspiracy. War between Florence and Sixtus’s Papal States followed, with peace restored only two years’ later. The whole affair was a complete mess, and backfired for Sixtus as Lorenzo tightened his grip on power in Florence. The Pazzi conspiracy was a bleak illustration of how Sixtus’s grasping for territory intended for his family could have unintended and uncontrollable consequences.
Other meddling and scheming by Sixtus to advance the della Rovere would meet with more success. Sixtus liked to stress his humble origins, and though he was not the lowly rustic everyman he liked to pretend, his family name was as nothing compared to the noble houses of Italy. He claimed relations with a noble branch of the della Rovere family, even adopting their coats of arms, but the connection was at best tenuous. More concrete measures were needed, and as usual, Sixtus looked to his nephews. He arranged the marriage of his nephew Giovanni with Giovanna da Montefeltro, daughter of the powerful Duke of Urbino. Their son Francesco (below) inherited the duchy in 1508.
In Rome, the other chief aim of Sixtus’s pontificate, rebuilding the city and leaving the della Rovere mark on it, brought long-lasting results. An important feature of Sixtus’s reign that affected the appearance of Rome was legislative. Previous popes had possessed the right of confiscating the property of rich and powerful families who crossed them. Sixtus decreed that henceforth clerics could pass on buildings to their heirs. This allowed them to spend lavishly on property, secure in the knowledge that they wouldn’t be seized by the Vatican.
Sixtus’s own projects included the Ponte Sisto, a footbridge north of Tiber Island, built in 1479. It was the first bridge to be built in the city since the age of the Caesars. It combines practicality with a simple, aesthetic beauty, and includes an oculus at its centre to relieve pressure when the Tiber is in flood. The need for a new bridge linking the Vatican to the Campus Martius had become urgent following the jubilee year of 1450, when thousands descended on Rome on pilgrimage. The ramshackle city was not prepared for such numbers and was ill-equipped to serve and protect them, the most disastrous illustration of which was a deadly crush of worshipers on the Ponte Sant’Angelo.
Sixtus’s new bridge, built on the foundations of an ancient predecessor (Pons Aurelius) by Baccio Pontelli, was urban infrastructure to facilitate the flow of pilgrims to St. Peter’s; more than this, it was an invitation for more visitors, a sign that Rome was looking to the future yet also reasserting its old title, caput mundi. The Ponte Sisto’s design was based on that of ancient bridges, a clear attempt to connect the imperial power of the Romans with the spiritual empire of the Catholic Church.
Two marble inscriptions on the bridge point to another of Sixtus’s interests. They were written to commemorate Sixtus’s role in the bridge’s construction by the humanist scholar, author and librarian Bartolomeo Platina. Sixtus’s interest in and support of humanism is another striking feature of his pontificate. It was genuinely felt, too. As a young man, Sixtus studied at the thoroughly humanist University of Pavia. Our modern understanding of ‘humanism’ might cause us to ask how an adherent could become the head of the Church, but in Sixtus’s day a humanista was somebody who studied or admired literature that was non-divine, in other words, the philosophical, dramatic and rhetorical texts of classical Greece and Rome. Such students read humanae litterae – human literature, as opposed to divine works such as the Bible. Translation of such texts, and the rediscovery of antique knowledge, was to many scholars across Europe a thrilling intellectual pursuit.
Printing presses made it much quicker to disseminate such translations, but this explosion of rediscovered texts was by some treated with suspicion, and as an affront to tradition in their potential to undermine sacred beliefs (as the Protestant Reformation would so vividly demonstrate). Under Sixtus’s predecessor Paul II, Platina had been imprisoned and tortured at Castel Sant’Angelo on charges of heresy and of being party to a conspiracy to assassinate the pope. This rumour derived from papal suspicion of the Roman Academy, of which Platina was a member, and its propagation of humanist and Neo-Platonic ideas. Platina was a friend of Sixtus, and that he inscribed the Ponte Sisto reveals both the vagaries of patronage in Early modern Europe and the extent of Sixtus’s humanist credentials. Under Sixtus, Platina became papal librarian, and wrote a history of the popes that dwelt on the ancient history of the city. The renewed interest in antiquity, fuelled by manuscripts and humanist literature, helps explain Sixtus’s donation to the people of Rome of the Lupa Capitolina, the Spinario and the gigantic head of Constantine, all of which remain in the Capitoline Museums.
A fresco of Sixtus by Melozzo da Forlì, now in the Pinacoteca at the Vatican, neatly coalesces Sixtus’s humanist sympathies with his unwavering commitment to raising his family’s status. The occasion is the formal inauguration of the Vatican Library, and shows Sixtus seated and a kneeling Platina, the library’s prefect, in front of him pointing to his inscription. The other individuals depicted are the della Rovere nephews, Giuliano (centre) and his brother Giovanni (far left) and their cousin Girolamo Riario (behind Platina). The figure behind the pope’s chair is likely Pietro Riario, a cardinal and Girolamo’s older brother, who had died in 1474. Stuffed with family members, no image better summarises Sixtus’s reign; the setting is also noticeably classical with an egg and dart cornice, Corinthian capital, arch, columns and gilded-coffer ceiling – a flaunting of Sixtus’s classical leanings.
Though the room most associated with the Renaissance in Rome, the Sistine Chapel, bears Sixtus’s name, he is responsible for only part of the decoration. Michelangelo’s Sistine Ceiling and Last Judgement altar fresco came the following century (a fresco on the altar wall by Perugino¸ the Assumption of the Virgin, in which Sixtus featured, was destroyed to make way for the Last Judgement). However, the narrative works running parallel on the Chapel’s walls, commissioned by Sixtus, survive. These are usually overlooked by the harangued visitors to the chapel today, who are understandably drawn to Michelangelo’s work above their heads. But these narrative cycles are the fruits of the most accomplished painters of the age: Botticelli, Perugino, Ghirlandaio, Rosselli and Signorelli. They depict on one side the life of Moses, and on the other the life of Christ, and are thematically matched – Botticelli’s Temptation of Christ, for example, faces his Trials of Moses on the wall opposite.
An irony of the whole Sistine Chapel decorative enterprise is that among its painters were the Florentines Botticelli, Ghirlandaio and Rosselli. They had been sent to Rome as a gesture of good will by Lorenzo de’ Medici just two years after the Pazzi conspiracy had so dramatically failed at its attempt to remove the Medici from power – an event in which, as we have seen, Sixtus was implicated. Those two years had seen war between Sixtus’s Papal States and Lorenzo’s Florence. As noted by John Marciari, during this period Botticelli had not only produced a fresco of the hanged Pazzi conspirators for Florence’s Palazzo Vecchio, but had also undertook a posthumous portrait of Giuliano de’ Medici, Lorenzo’s brother who had been hacked to death as part of the plot. Medici revenge was delayed but sweet. Long after Sixtus’s death, the decision to replace Perugino’s Assumption of the Virgin – in which Sixtus was depicted – with Michelangelo’s Last Judgement was made by Pope Clement VII: Giuliano de’ Medici’s son.
 Christopher Hibbert 1985: 126
 John Marciari 2017: 77
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