The Mongols

Are the Mongols worse than the Canadians?
Lets see. Massive winning record followed by nothing but disappointment and failure.
I'd say they are pretty much the same.
Great, now I am sad.
 
Not widely advertised fact is that the Muslims even raped the knights they captured. They literally fucked anything that moved. Thus was opened the largest slave market in the history of humanity that lasted for the next 500 years. It rivaled Rome and then surpassed it.
 
Persia is situated in a bad location.

They were marched over by Alex the Great on his way east.

Then they were marched over by The Mongols on their way west.

Finally, they were conquered by the Muslim Arabs and forced to convert to Islam (or be killed).