[Steve Van Doorn]

I agree there were other raiders. This all boils down to these raiders made the roads and the seas unsafe and trade nearly stopped. This is what created the dark ages.

I have to point out Islam was the worst of these groups and they controlled the seas raiding at will.

When Rome controlled the seas and roads they were relatively safe for trade.

[Sherman Logan]

You may be right. And Islam got started a good deal earlier than the Vikings and Magyars, whose attacks may very well have been made easier by the general decline of Europe.

[Sherman Logan]

Doesn't present violence, they persisted, have its roots in the Crusades' brutal, unprovoked attacks against a sophisticated and tolerant Muslim world?

The Crusades were a minor blip in Muslim history, peripheral in both time and space.

MUCH more central to Muslim history of the time were the Mongol conquests.

From before 5000 BC straight thru to the Mongol invasions of the 1200s what is now Iraq was continuously a thriving home of civilization.

Conquerors rode thru, raped and pillaged and destroyed irrigation works. The surviving peasants always rebuilt them.

The Mongols rode thru, raped and pillaged, destroyed the irrigation works, and then killed all the peasants. The area has never recovered.

Similar stories apply in Iran, Central Asia, etc. Muslims didn't take well to pagan Mongol rule, and the Mongols didn't handle resistance well.