In the period of the year 500 to 1000, a lot happened in the field of religion. The two largest religions the world now knows have then spread. It is also almost impossible for these two religions to meet each other. They both wanted to enlarge their territory and met in Spain and eastern Europe. These two religions are Islam and Christianity.
Christianity was already fairly spread across Europe at the beginning of the early Middle Ages. In the Roman empire, this religion had been state religion. Because of this, in the area where they had ruled everyone was obligated Christian. Islam was not even born at the beginning of this period. Islam is a fairly young religion. It only emerged in the year 610. This was the year the Prophet Mohammad received his first revelation. He quickly gained many followers. These followers called themselves Muslims. In the beginning the Muslims were persecuted. Just like the Christians. But it wasn't long before the great leaders of the Middle East converted to Islam.
But while the Roman Catholic Church still determined which rules of faith christians should abide by, Islam did not. The Islamic lands were ruled by a caliph. The caliph had little to say about the content of the faith.
After the fall of the Western Roman Empire, the Roman Catholic bishops were in charge in the major cities. A king could only seize power if he received the support of the Catholic Church. That's why King Clovis was baptized. He was the first Frankian king to become a Christian. And because he was baptized, Christianity also grew in his country. The Pope thought it was very important that as many people as possible become Christians. He sent missionaries to the countries where few people had been baptized. These missionaries were mostly Irish monks. The Irish monks told not only about Jesus, (the most important person in Christianity) but also about the most important principles of Christianity. These were: celibacy, poverty and obedience.
The most important monk of history was Willibrord. Willibrord came from Ireland to the Northern Netherlands in 690. He lived near Utrecht and has converted many Dutch people to Christianity. Below were also many noblemen. If a nobleman or knight converted, the Catholic Church could build a monastery on his land. That's why Willibrord tried to convert as many noblemen as possible.
Many young men went to live in the monasteries. This was the best way for them to practice their new faith. They became celibate monks. This meant they would never get married. In the monastery, the men learned to read and write. Most people at the time couldn't do this. The monks copied a lot of old books. In the eighth century, a huge number of books were copied. At this time Charlemagne was king of Western Europe. That's why we call the time when so many books were copied the Carolingian renaissance.
In the ninth and tenth centuries, many books were also written in the Middle East. The Muslims had preserved many philosophy books from history. These came from the time of the ancient Greeks. They translated these books into Arabic and Latin.