His Latin name—Carolus—has passed into many modern European languages such as Polish (król), Bulgarian (kral), Czech (král), and Hungarian (király) as the literal meaning for “king.”5 And his political achievement has been just as long-lasting. Uniting the lands on either side of the Rhine into a superstate centered on modern France and Germany took monumental effort. Keeping them together proved beyond the capabilities of most of Charlemagne’s successors.
