Explanation: Genghis Khan sent envoys to the Khwarazmian Empire to normalize trade relations between the then-new Mongol Empire, and the long-established Khwarazmian Empire. Genghis made certain to send Muslim subjects of his as envoys to minimize the chance for religious-cultural offense.
The envoys were accused of being spies, seized along with their goods, and executed.
Genghis Khan sent another group of envoys to emphasize that his intentions were peaceful and that the only interest was in normalizing trade and ensuring the safety of his subjects in any future negotiations.
They were also executed (or according to some accounts, one was executed and the other two were humiliated and allowed to return to Genghis to deliver the Khwarazmian message of 'no').
Genghis then invaded the Khwarazmian Empire and destroyed it entirely within two years.