After Charlemagne's death, his empire was passed to his son, Louis the Pious.

Louis struggled to hold the vast and diverse empire together.

After Louis's death, a civil war broke out among his three sons: Lothair, Louis the German, and Charles the Bald.

The brothers fought for control of the empire, each seeking to maximize his own inheritance.

The Treaty of Verdun, signed in 843 CE, formally ended the civil war and partitioned the Carolingian Empire.

The empire was divided into three separate kingdoms.

Charles the Bald received West Francia, which would eventually become the Kingdom of France.

Louis the German received East Francia, which would become the Kingdom of Germany.

Lothair, the eldest, received the imperial title and Middle Francia, a long and vulnerable strip of territory between the other two kingdoms.

This treaty marked the definitive end of Charlemagne's unified empire and laid the groundwork for the political geography of modern Europe.