At the start of the fifteenth century, Rome seemed to be at the end of a long decline. The skyline was littered with the ruins of once spectacular structures. Wild animals ran free through the overgrowth dominating the center of the city. The city that had dominated the entire world centuries earlier was a shadow of its former self. In the first century, Rome had a population of about one million. At the start of the fifteenth century the city held perhaps 25,000. Rome was not a great center of commerce, and the papacy, which had long sustained the city through its riches and international influence, had moved from Rome to Avignon during the fourteenth century.
In 1420, the papacy returned to Rome under Pope Martin V. During the coming centuries the papacy would rebuild the city, and the Papal States, centered in Rome, would assume a position of great importance in Italian affairs. The papacy closely supervised the Renaissance evolution of Rome, maintaining its economic power, and thus control of the city, through the sale of church offices and taxation of the Papal States. Throughout the fifteenth and sixteenth centuries, papal holdings experienced periodic spurts of support for political independence from church control. But the papal grip was tight, and the destiny of city and church remained inextricably intertwined.
After the return of the papacy, the first step in resurrecting Rome was the ascension of Pope Nicholas V in 1447. As a monk in Tuscany, Nicholas V had been helped financially by the Florentine banker Cosimo de Medici, who had lent him money without asking for collateral. As a result, Nicholas appointed Cosimo Papal banker. Financed by the Medici family, Nicholas set about founding the Vatican library. He collected influential works of the ancient scholars from all corners of the continent. When Constantinople fell in 1453, Nicholas V purchased many of the vast number of Greek volumes left ownerless. He instilled the value of learning at the Vatican, spurring the beginning of intellectualism in Rome. In his eight short years as pope, Nicholas V achieved miracles of destruction and reconstruction in Rome, beginning the changes that would transform Rome into a Renaissance city capable of contending with the splendor of the North.
The Papacy continued to be a force for change in Rome. However, as Rome became wealthier and more powerful corruption in the Papacy grew. The pattern continued throughout the fiteenth century. With the election of Pope Sixtus IV in 1471, the Papacy began a plunge toward moral degradation while Rome itself ascended to the greatest splendor it had achieved since Roman times. Under Sixtus IV, nepotism reached new and corrupt heights. Sixtus' 'nephews' (the papal nephew was a long-standing way of referring to the pope's illegitimate children) were granted influential posts and huge salaries. Sixtus IV even entered into a conspiracy to have the powerful Medici family assassinated when he thought they were getting in one of his nephew's way. This model for papal rule was followed throughout the Renaissance, undermining papal moral authority, but allowing the Papacy to grow politically and economically strong.
Yet at the same time, Pope Sixtus IV took great strides to redesign and rebuild Rome, widening the streets and destroying the crumbling ruins. He commissioned the construction of the famed Sistine Chapel and summoned many great Renaissance artists from other Italian states. As Rome was gradually transformed and infused with wealth, artists flocked to the city seeking Roman gold. In receiving it, they redecorated and rebuilt almost all of Rome.
The Middle Ages had not been kind to the city of Rome. As the darkness of medieval times had obscured the glory and intellectualism of the Roman Empire, it had also descended physically on the former center of the empire. Citizens of Rome felt little attachment to their historical roots, and thus saw no reason to expend a great deal of energy preserving the city. The glorious buildings of Rome thus began their long decline, at the mercy of looters and thieves. Without the protection of the citizens, the buildings began to crumble and many became less and less visible as dirt and waste built up around them. The fourteenth century schism in the Catholic Church, which caused the Papacy to move its headquarters to Avignon, was the final crushing blow for Rome, which suffered from the removal of wealth and power and became a city of poverty and sadness. The Romans of the fourteenth century had forgotten the glory of centuries past and saw no hope of ascending to new heights in the present. They watched as the northern cities began to flourish during the late Middle Ages due to the rise of commerce, and many emigrated in the hope of bettering their position in life.
Finally, in 1420, the first glimmer of hope appeared for Rome to catch up to its northern rivals. The Papacy returned to Rome and brought with it the wealth and prestige Rome needed to ascend once again to great heights. The pope came to power in a situation far different from that of any other monarch. The papacy was responsible not only for the international Catholic Church, whose components were inextricably bound to politics all over Europe, but also headed the government of the turbulent Papal States in Italy. This was often cause for conflicts of interest that the pope had to address in such a manner as to accommodate the needs of as many of his constituents as possible. Further, the pope had to make these frequent tough decisions without the backing of a royal family, a strong support system upon which every other monarch in Europe depended. Having no official direct heirs, the pope often turned to Papal nephews, who, while claimed to be the children of his brothers and sisters, were more often the illegitimate children of the pope himself. During the Renaissance, the importance of the nephew (nipote) as an aid and confidant grew greatly, and the Papal nephew was often the recipient of the pope's good will, receiving influential positions and large salaries. While nepotism was common practice among the Renaissance popes, most popes did little harm by it. Others, however, like Sixtus IV, substantially weakened the moral authority of the Papacy and turned many of his advisors and cardinals against him.
Perhaps even more important than the return of the Papacy to Rome was the connection established with Florence by appointing Cosimo de Medici Papal banker. If Florence benefited from its role in the handling of Roman gold, Rome benefited even more from the infusion of Florentine ideas, and eventually immigrants. In this way, Rome rode the tide of the Renaissance that had grown strong in Florence, absorbing the principles of humanism and the new intellectualism flowing from the north along the pipeline of communications established for financial purposes. By the latter fifteenth century Rome could finally be said to have become a peer of the northern city-states, and its power showed no sign of fading.