Saint Achilles, Bishop of Larissa, lived during the fourth century, during the reign of St Constantine the Great. Glorified for his holiness of life and erudition, he was made Bishop of Larissa in Thessaly.
St Achilles participated in the First Ecumenical Council, where he boldly denounced the heretic Arius. In his city he strove to promote Christianity, destroyed idolatrous pagan temples, and he built and adorned churches.
St Achilles had the gift of healing sickness, especially demonic possession, and he worked many miracles. The saint died peacefully in about the year 330. His relics have been in Prespa, Bulgaria (now the village of Akhila, renamed in honor of the saint) since 978. SOURCE: