Answer:
1. The Fall of Western Roman Empire (476 AD)
2. Charles the Hammer and the Battle of Tours (732 AD)
3. Charlemagne, the Emperor of Romans (800 AD)
JUST SOME INFO:
The downfall of the Roman Empire in the west led to the formation of the Frankish states in the late 15th century A.D.
The fertile plains, land, cattle, weapons , and horses attracted the Frankish nobility.
The Battle of Tours was encountered among Franks and Burgundian against the Muslims in 732. The leader of the battle from the Christian side was Charles Martel. He played a significant role in defeating the army of Spanish Moors who were trying to enter Western Europe.
Charlemagne (called Charles I) was king of Frank and Lombards, and under Pope Leo III, crowned as the emperor of Rome in 800 A.D. He was known for his military skills and political capabilities.
Thus we can conclude that the events like the fall of the Roman Empire, The battle of Tours and the founding of the Holy Roman Empire played a vital role in the Middle Ages in Europe.