Different civilizations have different ideals, beliefs, and attitudes, which may not be compatible with those of other civilizations, so when two civilizations encounter each other in some manner (immigration, war, the internet, etc.) there can be a conflict that results. We can call it a clash of civilizations.
For the same reasons modern civilizations had slaves. To do work and serve the masters
The Middle Ages began after the collapse of the Roman Empire.
Cahokian.
Rome
there is limited coverage for collapse - it would depend on the root cause of the collapse
Mesopotamia
they collapse in the 900s
It ruined
The root word for collapsible is "collapse."
earthquakes and floods
Rime
what cause the collapse of hedge fund in this case
The word 'collapsible' is the adjective form of the verb to collapse.
Can cause the roofs of buildings to collapse.
barberians
cause