Convention dictates that modern times began around 1500. Ancient civilizations like the Greeks and Romans exercised tremendous influence on what would become Europe, through contributions to philosophy, science, law, and government. In order to understand the history of the modern world, we must not only examine Europe and its rise to ascendancy, but also the influences of other cultures and civilizations upon Europe. The spread of Christianity, which began in the Roman Empire and continued into the early Middle Ages with the conversion of non-Christian tribes and the peoples of eastern Europe, gave Europe a common religion. The growth of the church and the increasing power of the papacy laid the groundwork for an ongoing struggle between secular and religious powers. In the Early Middle Ages, Europe underwent social, economic, and political transformation–agricultural innovations encouraged population growth, towns and commerce flourished, and feudal relations laid the foundations of national monarchies. By about the year 1300, Europe had become a recognizable geographic, cultural, and political entity among the Mediterranean civilizations into which the Greco-Roman world had divided.