Saint Achilles, Bishop of Larissa, lived during the fourth century, during the reign of Saint Constantine the Great. Glorified for his holiness of life and erudition, he was made Bishop of Larissa in Thessaly.
Saint 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.
Saint 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 are in Prespa, in today's Republic of Macedonia, since 978.