Gadevang Man. Well-preserved skull of Gadevang Man, a 'bog body' dated 480-60 BC. The skull shows a circular 3 centimetre diameter opening due to a surgical trepanation procedure. The skeleton of this man aged 35-50 was discovered in 1940 during peat cutting in a bog on Sealand, Denmark. This operation of cutting a hole through the skull may have been performed to remove a blood clot or even a spirit. Gadevang Man survived the procedure because the hole shows healed edges. Many ancient bog bodies of northwest Europe met violent deaths by murder or religious sacrifice. Low temperature & oxygen, & tannins in bogs preserved the bodies.