After the end of the late Middle Ages period, the Renaissance would spread unevenly over continental Europe from the southern European region. The intellectual transformation of the Renaissance is viewed as a bridge between the Middle Ages and the Modern era. Europeans would later begin an era of world discovery. Combined with the influx of classical ideas was the invention of printing which facilitated dissemination of the printed word and democratized learning. These two things would lead to the Protestant Reformation. Europeans also discovered new trading routes, as was the case with Columbus’s travel to the Americas in 1492, and Vasco da Gama’s circumnavigation of Africa and India in 1498. Their discoveries strengthened the economy and power of European nations.

Along with the invention of printing, and the associated dissemination of the printed word, what other factor is believed to have led to the Protestant Reformation?