As ancient Greeks started looking for deities that could fulfil the pragmatic needs of common people, local heroes started being mythologized and worshipped through cults. The most widespread such example was Asclepius, possibly a skilled war surgeon who followed military expeditions to Colchis and Troy. He was worshipped at religious temples called Asclepieia where certain specific medical and surgical techniques were followed. The most advanced must have been skull trepanation, most likely done as an acute operation to release intracranial pressure. The contemporary Hippocratic corpus provided extensive descriptions of the technique and archaeological evidence have shown that many patients survived the operation. Decompressive craniectomy techniques have been practiced for millennia but it is possible that they were first systematized as a neurosurgical innovation through the Ancient Greek religious cult followed in Asclepieia.