The Frankish Empire was a powerful realm in Western Europe during the early Middle Ages, primarily established by the Franks, a Germanic tribe. It reached its height under the rule of Charlemagne, who became the first Holy Roman Emperor in 800 AD. The empire played a crucial role in the spread of Christianity and the unification of various tribes and territories. After Charlemagne's death in 814 AD, the empire began to fragment due to internal conflicts and external pressures. It was eventually divided among his grandsons in the Treaty of Verdun in 843 AD, leading to the formation of separate kingdoms that laid the groundwork for modern European nations.