Irmenach's and Beuren's beginnings are shrouded in darkness. There are known to have been settlers in the area as early as Roman times. An old local tradition has it that the name Irmenach goes back to Saint Irmina, which is, however, hardly likely. A far greater likelihood is that it came from "Herminiachus" (“Herminius’s Estate”), in which Herminius was a Celtic nobleman who had Latinized his name. Originally, Irmenach formed, together with Beuren and Thalkleinich, now an outlying centre of Kleinich, the greater municipality of Irmenach, which existed until 1828.