The story of Italy from the dawn of the Renaissance in the 15th century to the Age of Enlightenment in the 17th and 18th centuries is as varied and fascinating as that of the rise and fall of the Empire.
Despite the centuries that had passed since the collapse of the Roman Empire, the age of siege wasn't yet over. In 1527, Charles V, king of Spain, carried out the worst sack of Rome ever. To the horror of Pope Clement VII (a Medici), the entire city was brutally pillaged by the man who was crowned Holy Roman Emperor the next year.
During the years of the Renaissance, the Reformation, and the Counter-Reformation, Rome underwent major physical changes. The old centers of culture reverted to pastures and fields, and great churches and palaces were built with the stones of ancient Rome. This construction boom did far more damage to the temples of the Caesars than any barbarian sacking had done. Rare marbles were stripped from the imperial baths and used as altarpieces or sent to lime kilns. So enthusiastic was the papal destruction of imperial Rome that it's a miracle anything is left.
This era is best remembered for its art. The great ruling families, especially the Medicis in Florence, the Gonzagas in Mantua, and the Estes in Ferrara, not only reformed law and commerce, but also sparked a renaissance in art. Out of this period arose such towering figures as Leonardo da Vinci and Michelangelo. Many visitors come to Italy to view what's left of the art and glory of that era, including Michelangelo's Sistine Chapel ceiling at the Vatican.