In the Roman Empire, hostelries called mansionis were situated along the Roman road system to accommodate travelers on government or commercial business. It was a kind of Roman lodging-house. In the Roman Empire, communications were carried along main roads and the houses were used for overnight stays. They were spaced one day's journey apart. They usually had a defended post, with a ditch, rampart, gatehouses with guardrooms for the road police, and a canteen or taberna. Between these rest houses were mutationes with stables for changing horses and a taberna for refreshing the riders.