How did the population of Europe change in the Middle Ages? What role did internal colonization play in the economic life of Europe?

By the time the Middle Ages began, the population had dropped significantly, from nearly 60 million to 30 million. This resulted in frequent epidemics and reduced yields.
For almost 4 centuries, from the 6th to the 10th century AD, this value remained practically unchanged.
Then, in the next 3 centuries, the population increased several times. The reason for this was the stabilization of the political and military situation in central Europe, as well as the development of agriculture and the revival of cities.
Since the beginning of the 14th century, due to the great famine in 1315-1317, the population has decreased by 15-25%.
Then the mainland was covered by a plague epidemic, and many countries began to wage active hostilities.
From the beginning of the 16th century, the population began to gradually increase again.