How did Charlemagne create an empire that blended several different traditions?

He used a combination of his personal charisma and intelligence, the feudal system, the Church, and war in order to create the greatest Empire since the time of the Romans. His dislike of corruption, and his power in battle all contributed to his success as Emperor.

Charlemagne himself was the key to his own success. He himself was a charismatic man, with an incredible amount of vital energy, and a desire to do well. An example of this was that he studied a lot, and made "heroic efforts" to learn to write, according to Einhard, his biographer. As we will see later on, education was a major part of Charlemagne's regime. He also was an honest and normal person, and disliked the regal trappings of his court.