Sacking of Baghdad 1258 by the Mongols. Pretty much the standard event for the end of the 'Golden Age of Islam' although this may be disputed by a few decades in some circles.
In any event, no sign of your demonic 'conservative governments'.
http://www.historytoday.com/richard-cavendish/baghdad-sacked-mongols
If you have any examples backing up your claim, please feel free to post away.
