The Dark Ages, the Age of Faith, the Age of Chivalry, the Age of Feudalism, the Golden Age of Europe. The Middle Ages have been referred to with many different labels. All have evidence to support their validity, but some have more claim than others.
Faith. The one thing that medieval folks had more of than anything else. They believed mostly because it gave them a purpose, something to look forward to. Christianity was and still is a religion that appeals to people of all classes and backgrounds. It used the basic principle that everyone was eligible for salvation, as long as you followed the Divine Law, and repented your sins. In no other time were the people so in touch with God and their religious side. For this reason, the Church was able to exercise a great amount of influence over the people. For example, it was able to order and lead the people into battle against the Muslims in the "holy wars" called the Crusades. The early Crusades were huge examples of the Church's amazing power. In the long run, it weakened the power of the Pope; however, it did nothing to lessen the great "religious fervor" that had formed. In this time, the Roman Catholic Church was the major unifying force.
Many highly educated historians think of the Medieval period as the Dark Ages, and rightly so. The Middle Ages was a time that suffered a decline in learning, and the loss of a common language. The years in which the Bubonic plague struck were also considered to be very dark. The Plague wiped out nearly one-third of the population, which translates into about 25 million people dead in Europe alone. It was also a time of great unrest and warfare. In most regions, chaos reigned supreme. There were numerous invasions on European soil. The notorious Vikings were one such group of invaders. The Magyars and Muslims also attacked much of Eastern and Southern Europe. Kings that oversaw large areas could no longer rule. This led to more local leaders that could support an army. Eventually, Feudalism evolved from this situation.
In the Medieval Period, the predominant form of government became feudalism. Feudalism was a very complicated system that relied on mutual obligations between all levels. If someone did not uphold their obligation, the whole system collapsed. The Feudal system was shaped like a pyramid. The King was at the top. The Church Officials and Nobles were on the second level. Knights came next on the third. Last and certainly least were the peasants and serfs that made up the majority of the population. Your status in the Feudal pyramid was generally inherited. Feudalism was a very large part of medieval society. Thus, it is deserving of the title, "The Age of Feudalism."
The Age of Faith is most appropriate title for this time period. Faith was just as much a part of the social customs as actual belief. There were not many non-religious people around. Even if deep in their hearts they did not believe, they still went through the actions of faith so as not to be shunned by their peers. However, most people did genuinely believe. They prayed for the strength to stay on the correct path that would take them to Heaven and eternal bliss.