Clastidium (modern Casteggio), was a village of the Anamares, in Gallia Cispadana, on the Via Postumia, 5 miles east of Iria (modern Voghera) and 31 miles west of Placentia.Here in 222 BC, Marcus Claudius Marcellus defeated the Gauls and won the spolia opima; in 218 BC, Hannibal took it and its stores of corn by treachery.