Imerius of Immertal was a monk and missionary who lived in the Swiss Jura region during the late sixth and early seventh centuries. Born in the village of Lugnez, he traveled to Lausanne and eventually made a journey to Palestine. Upon his return, he settled in the valley of Saint-Imier to live as a hermit. His historical influence is reflected in the local geography, as the names of the towns Saint-Imier and Saint-Ismier are derived from his name.