Most historians consider the city-states of Northern Italy, particularly Florence, to be the birthplace of the European Renaissance. A number of things all came together in this region at about the same time to lead to a rebirth in learning and classical culture.
One of the main contributing factors was the growth of trade and commerce. New trade routes around the Mediterranean and beyond meant that more wealth was available to merchants and bankers to spend on the arts and to dedicate time to scholarly pursuits. Wealthy families such as the Medicis spent vast sums of money as patrons of the arts. Traders also were exposed to new ideas as they traveled along their trade routes. They learned about different philosophies, technologies, and scientific ideas which they brought back home with them.
Another cause of the Renaissance was the end of the Crusades. For centuries the Arabs had been custodians of Classical knowledge. They had preserved many works of ancient literature and learning in their libraries. Europeans who traveled east during the Crusades often returned with rediscovered knowledge of Classical learning, arts, and philosophy. The works of Greek and Roman poets, playwrights, mathematicians, and philosophers that had been lost to Europe for so long were now returning with the crusaders. Italy was often one of their first ports of call in Europe. This sparked a renewed interest in the Classics.
Furthermore, by the fourteenth century, feudalism in Europe had been on a steady decline. A weakened nobility and a more empowered peasantry meant that new opportunities were open to people who had previously been shut out from social and economic advancement. Aided by the printing press, people were being exposed to new thoughts and ideas that made it possible for European society to shift away from the old medieval systems and towards what became known as the Renaissance.