The name was formerly rendered as "Irish mountain", referring to the monk Marinus, who settled in the area in the course of the Hiberno-Scottish mission under Pope Eugene I and, according to legend, about 697 was martyred by burning at the stake (see the coat of arms).
Since 1983 he is a member of the Zentralkomitee der deutschen Katholiken (Central Committee of German Catholics – and its president since 2009), the chairman of the Bergwacht Bayern (Mountain rescue Bavaria), of the charity association Caritas Children's Village Irschenberg, and of the Freundeskreis Abtei Frauenwörth (Circle of Friends Frauenwörth Abbey) on Frauenchiemsee as well as the vice chairman of the Hanns Seidel Foundation.
The local government of Irschenberg are planning the construction of a motorway exit with a fast-food restaurant, for which they need the property of Magdalena Trenner, a rich old woman who is unpopular in the village until she takes in a traveling carpenter, Johannes, and later an asylum seeker named Theophile.