What term doesn't belong : gunpowder, calvary, fake retreat, psychological warfare

Calvary

Explanation:

I Think its Calvary because gunpowder, psychological warfare, and fake retreat are acts during war that can influence your enemy but the Calvary is a title of horsemen that charge into battle.

Gunpowder affects the mind after a while making you woozy during battle and you start to get headaches from it (especially during the 1800's nobody drank water really).

Psychological warfare can instill fear into the hearts of your enemy for instance Vlad the Impaler impaled over 1000 prisoners on the way to his fortress which instilled so much fear into the Ottoman army they turned back.

A fake retreat can make any enemy chase after you and if you have another army not too far away you can cut down the very tired imposing army.

they were byzantines

jewish people, gypsies, and political opponents.