Two 2,500-year-old bronze helmets caught in a fisherman's nets off the western coast of Mt Athos may have belonged to soldiers in a Persian fleet shipwrecked in the area in 492 BC, during the first of the empire's three great campaigns against Greece, archaeologists believe. The two fifth-century-BC helmets, of the Greek Corinthian type, were found 110 meters deep, off the skete (monastic retreat) of Aghia Anna at the southern tip of Mt Athos by a fisherman from the village of Sykia, on the Sithonia peninsula west of the Holy Mountain. He handed them over to the state archaeological service, and was given a 2-million-drachma (5,870-euro) reward. According to a paper to be presented in Thessaloniki on Friday during a three-day conference on last year's archaeological work in Macedonia and Thrace, the helmets could have belonged to the ill-fated Persian force of 300 ships and 20,000 men - according to Herodotus - lost in a storm off Athos. Many of the invasion troops would have been Greek vassals from the cities of Asia Minor that had been subjected to Persian rule.