Surgeons were carrying out complicated skull operations in medieval times, the remains of a body found at an archaeological dig show.
A skull belonging to a 40-year-old peasant man, who lived between 960 and 1100AD, is the firmest evidence yet of cranial surgery, say its discoverers.
The remains, found in Yorkshire, show the man survived an otherwise fatal blow to the head thanks to surgery.
Nearly 700 skeletons were unearthed by English Heritage at a site near Malton.
Scientists have been examining the remains from the now deserted village of Wharram Percy.
Once a thriving community built on sheep farming, it fell into steep decline after the Black Death and was eventually completely abandoned.
The skull in question, dating back to the 11th century, had been struck a near-fatal blow by a blunt weapon, causing a severe depressed fracture on the left hand side.
Closer examination revealed the victim had been given life-saving surgery called trepanning.
A rectangular area of the scalp, measuring 9cm by 10cm, would have been lifted to allow the depressed bone segments to be carefully removed.
This would have relieved the pressure on the brain.
Roman and Greek writings document the technique of trepanning for treating skull fractures, but there is no mention of it in Anglo-Saxon literature.
Some historians have theorised that western Europe was deprived of such surgical knowledge for centuries after the fall of Alexandria in the 7th century.