The Mongols sacked many cities over the course of their reign, but perhaps none so brutally as the Persian jewel of Nishapur in 1221. When they were done, giant pyramids of human heads stood where a majestic, cosmopolitan, Silk Road oasis had flourished only a few short days before. Be glad, so glad, you never lived on the wrong side of Genghis in this unbelievably bloody edition of Timesuck.