Why did knights use chain mail for protection and armor during The Middle Ages?

Surprisingly, chain mail was really good at protecting against arrows and bludgeoning weapons during the Middle Ages.

Soldiers who could afford and wear chain mail also wore leather tunics underneath, to keep the rings from being driven into their skin if they were clubbed.

They relied heavily on their shields for defense as well.

So chain mail was great—flexible, relatively light and effective against most weapons.