It’s dangerous to make history. Schoolchildren learn that Oliver Cromwell overthrew the British monarchy, but they’re less often told of the grisly price he paid.

Three years after his death of malaria, Cromwell’s body was dug up and underwent a “posthumous execution” for treason by the restored monarchy: It was hanged, drawn and quartered, decapitated and thrown into a common pit, and the severed head was mounted on a pole and displayed outside Westminster Abbey for four years, until 1685.

Even that wasn’t enough. The head passed among various owners for 275 years; it wasn’t buried until 1960, on the grounds of Sidney Sussex College, Cambridge.

And Cromwell was only the most prominent of the regicides of Charles I. Three others were also “punished” posthumously, and those still alive were imprisoned or chased out of England.