Reading the history of some of the ottoman sultans is depressing. Stories of endless concubines, wastefulness, binge drinking, etc It really goes to show that not all of the leaders of muslim countries or empires were immune to evil. For a case example, look up Sultan Ibrahim. The leader of the ottomans in the mid 1600s who kept concubines, was known for wastefulness and extravagance and died by execution for his crimes.

I am not mentioning his example in order to defame the Ottoman history, I use to to show that even some muslim rulers were vulnerable to sin and did indeed fall into it. Muslim leaders are not always sinless, good-doers but humans just like you and I. Jazakallah Khair to the "Lost Islamic History" for being brave enough to mention some of the not-so-nice parts of muslim history. NOTE: All of their posts are always positive and shed positive light on muslim history, however, this was just one example used to show the darker side of history as well. 

We must learn from our history, both the good and the bad parts, if we wish to progress as a society. Insha'Allah! ~A1