Trepanning is a process whereby a hole is drilled in the skull, and, with evidence going back to prehistoric times, it is one of the oldest surgical practices in history. The earliest trepanned skull was discovered at a Neolithic burial site in France, and is more than 7,000 years old. It may have had a practical effect – to relieve pressure on the skull after an injury – but it could have also been used to give a trapped demon a hole to escape, or so it was believed. Many different civilisation