[struggle]

I disagree because Islam had not been invented yet.

[nicollo]

I disagree because Islam had not been invented yet

Think again, Mohammad was born in c. 570 and the disruption of the period created the conditions for his take-over of Arabian peninsula, filling in the gaps left from Byzantium and Sassanid (Persia) decline as a result of these climate events.

Archeological digs in Arabian peninsula show a decided change in buildings during this period from trade-oriented structures to defensive ones.

See: "On the eve of Islam: Archaeological evidence from Eastern Arabia" by Derek Kennet (sorry no link)