Abbey of Saint Gall
Haslach was first mentioned in a document in the year 786. The document, a deed of donation, transferred ownership of some land from Heimo and his daughter Svanahilt to the Abbey of Saint Gall, including Haslach (then called Haslaha). Because there are no earlier mentions in records there is no way of telling how old Haslach really is, but it is clear that it was established sometime before 786.