What trend began with the coronation of Charlemagne in AD 800?

The coronation of Charlemagne as emperor in AD 800 is significant because it is often seen as a pivotal moment in the reintegration of Europe after the fragmentation that followed the fall of the Western Roman Empire. Charlemagne worked to unite a large portion of Western Europe under his rule, restoring a sense of centralized authority that had diminished in the post-Roman era. His reign marked the beginnings of what would later be known as the Holy Roman Empire, which played a crucial role in shaping medieval European politics and culture.

By promoting education, fostering the arts, and supporting the Church, Charlemagne not only solidified his own power but also contributed to the cultural and political cohesion of Europe. This led to the Christianization of much of Europe and laid the groundwork for the later developments in European history, including the feudal system and the eventual formation of modern European nations. Thus, the trend initiated by Charlemagne's coronation was indeed the reintegration of Europe, which had been divided into fragmented tribes and kingdoms.