I seem to remember, in the conquest of Baghdad, that the ruler had shot his mouth off about how he was going to beat the Mongols, until they arrived - then he begged for peace.
So the Mongols said “okay, but to show you really mean it send all your soldiers outside the city walls without their weapons”
Showing good faith, the Baghdad ruler did that.
And then, the Mongols killed everybody.
The Mongols were among the worst POS in history. OTOH, they were killing muzzies, so, everyone else wins.
How the Mongols Took Over Baghdad in 1258
https://www.thoughtco.com/the-mongol-siege-of-baghdad-1258-195801
…..And he is reincarnated into Joe Biden.