The Renaissance was a period of intellectual and artistic flowering that started in Italy in the 14th century and swept through Europe, lasting until the 17th century. Heralded as a rebirth of secular knowledge following the Middle Ages, it meant a revival of scholarly interest in the ancient Greek and Roman sources. During this period, the feudal system gave way to the growth of trade, the rise of the middle class, and the establishment of centralized government. In Italy, city-states arose, ruled by family dynasties such as the Sforza dynasty in Milan and the Medici dynasty in Florence. Statesman and political philosopher Niccolò Machiavelli outlined the ideal Renaissance leader in his book The Prince. The Renaissance was the age of global exploration. Such explorers as Christopher Columbus, Ferdinand Magellan, Hernán Cortés, John Cabot, and Vasco da Gama discovered new sea routes and new lands.