The first fortifications at the site were built by the Romans around 58 BC against incursions by the Helvetii. The fortifications were not sufficient, leading to direct war between the Romans and Helvetii. The defile became a significant trade route in following years. In 1184 a church and residence belonging to the Saint-Claude abbey was built on the site. During the Middle Ages tolls were collected for passage. In the 13th century a fortified house was built at the site by the Sire de Gex.

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