having or showing a very abnormal or sick state of mind the movie's villain was a just a clichÃ©d axe-wielding nutcase with a maniacal laugh Synonyms balmy, barmy [chiefly British], bats, batty, bedlam, bonkers, brainsick, bughouse [slang], certifiable, crackbrained, cracked, crackers, crackpot, cranky [dialect], crazed, crazy, cuckoo, daffy, daft, ...
His great empire stretched from central Russia down to the Aral Sea in the west, and from northern China down to Beijing in the east. On August 18, 1227, while putting down a revolt in the kingdom of Xi Xia, Genghis Khan died.
(which was almost immediately after he died). However, as with all Empires, it takes a strong man to maintain control over it. Once Genghis died, the Empire was divided up into different Mongol Khanates. Partially over inheritance confusion created by Genghis himself. However, what is essentially known as the Mongol Empire lasted for quite some time.