Scalping

Evidence exists of scalping in North America back to about 1325 or thereabouts, which if course means the indigenous population had been scalping for much, much longer than that. Natives to the continent, by and large war-like peoples, practiced all manner of body mutilation. Of course most other peoples did as well . . . from the Franks to the African tribes of Congo and beyond.

Scalping took many forms, but the manner in which we are most familiar with it involved putting the knee in the back between the victim's shoulders, pulling his head back by his hair and slicing the flesh between scalp an done, 2, 2 or 3 quick cuts allowed the whole scalps to be pulled away.

Here's a quick brutal example from Last of the Mohicans.