The Treaty of Verdun, agreed in August 843, divided the Frankish Empire into three kingdoms among the surviving sons of the emperor Louis I, the son and successor of Charlemagne. The treaty was concluded following almost three years of civil war and was the culmination of negotiations lasting more than a year. It was the first in a series of partitions contributing to the dissolution of the empire created by Charlemagne and has been seen as foreshadowing the formation of many of the modern countries of western Europe.

• Lothair I received Francia Media (the Middle Frankish kingdom).
• Louis II received Francia Orientalis (the East Frankish kingdom).
• Charles II received Francia Occidentalis (the West Frankish kingdom).