What are four seasons for the fall of the indus valley civilizations?

The collapse of the Indus Valley Civilizations can be attributed to the following factors. One, the trade networks declined and disappeared. This meant less work for traders and manufacturers. Two, changes in geography that caused the rivers to either dry up or change direction Three, the people abandoned the major cities. Four, without trade and access to water, people succumbed to disease and starvation.

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.