I have heard about how the Mongols would occasionally liquidate entire cities but how often have groups tried to eradicate an entire rival people or civilization leaving no one left alive? If it ever occurred why is it unheard of now?

by Derpese_Simplex
Celebreth

Sorry, we don't allow throughout history questions. These tend to produce threads which are collections of trivia, not the in-depth discussions about a particular topic we're looking for. If you have a specific question about a historical event or period or person, please feel free to re-compose your question and submit it again. Alternatively, questions of this type can be directed to more appropriate subreddits, such as /r/history or /r/askhistory.