 In medieval documents, the road is often referred to as the "Kaiserstraße", the emperor's highway, because over the centuries many high ranking personalities used the imperial highway.The Roman general Julian (359), the king of the Huns Attila (451), king Conrad III (1150), king Philipp of Swabia (1199), emperor Frederick II (1205), and king Henry VII (1224) all sojourned past the place where Horrenberg stands today.A valuable glass fragment from the 11th or 12th century found at castle Horrenberg indicates the passing of royal parties.