Answer:
The correct answer is: Weak leadership and external invasions.
Step-by-step explanation:
Emperor Charlemagne (742-814) ruled Western Europe during the middle ages for more over than 40 years. After his decease, his domains had to face the ineptitude of his new rulers -Charlemagne heir, who buy the year 800 did nothing but dissolve the Empire. In addition, external invasions from Muslims, Magyars, and Vikings in the upcoming century ended the supremacy of the western Europeans.