What role did medieval knights have in feudalism? They protected nobles and their land.
They protected serfs from their lords.
They protected the king from nobles.
They protected nobles from angry serfs.

i'm free to do it

explanation:

food chain i would say only because there is competition on getting food and survival

1. it was caused by feudalism

2. charlemagne used christianity as a major cornerstone for his rule. cloisters were built all over the empire to act as centers for the (re)population of the vast european wilderness.

3. the europeans feared the next raid every time chetak

i'm not so sure about #6. but i hope i you with the first 3.