The correct answer to this open question is the following.
Although there are options attached we can say the following.
Charlemagne attempted to change the education system in his kingdom during the Middle Ages in that he was a true supporter of quality education and ordered the construction of schools in his empire.
But first, he established a series of reformations, including education reformation. He demanded children in the court to study. Charlemagne himself set the example and started to study different lessons.
Some historians refer to the term "Carolinian Renaissance," to this period of reformation and taking the knowledge of conquered territories such as the Morish, the Lombards, and the Anglo-Saxons, to the empire.
Military invasions is the answer
