The Middle Ages
The Middle Ages begin with the fall of the Roman Empire (circa 400 CE) and end with the Renaissance, the Protestant Reformation, the discovery of the New World, and the Scientific Revolution (circa 1400-1600). The Middle Ages can be divided into three periods.
The Dark Age (The "Early Middle Ages")
The disintegration of the Roman Empire brings centuries of social chaos. Central government ceases, workers fall into serfdom, currency gives way to bartering, the academies shut down... Christianity, promising happiness in an afterlife, entrenches itself as the only tolerated religion.
During the later phase of the Middle Ages, the West gradually reorganizes. Trade and towns grow, nation-states consolidate (in part due to gunpowder), agricultural and navigational techniques develop, universities are founded.
The trends of the High Middle Ages come to a head in the Renaissance when conditions permit a rebirth of art and classical learning (e.g. Leonardo da Vinci, Shakespeare); Catholicism ("universalism") gives way to pluralism; and vast wealth begins to pour into Europe from overseas.