In the 9th century, Lorsch Abbey built the first church there, on the main peak, incorporating Roman construction; it was dedicated to Michael the archangel. The first written mention of the Heiligenberg, as Aberinesberg, dates to around 870, when abbot Thiotroch of Lorsch Abbey founded a monastery at the site of a former Carolingian royal estate. The church was first mentioned in 890/1.: