Issoire (Iciodurum) is said to have been founded by the Arverni, and in Roman times rose to some reputation for its schools. In the 5th century the Christian community established there by Stremonius in the same century was overthrown by the fury of the Vandals.
During the religious wars of the Reformation, Issoire suffered very severely. Merle, the leader of the Protestants, captured the town in 1574, and treated the inhabitants with great cruelty. The Roman Catholics retook it in 1577, and the ferocity of their retaliation may be inferred from the inscription ”Ici fut Issoire” (”Here was Issoire”) carved on a pillar which was raised on the site of the town. In the contest between the Leaguers and Henry IV, Issoire sustained further sieges, and never wholly regained its early prosperity.