Robber baron or robber knight is a historical term and title of disdain that was applied to the behavior and practices of a group of unscrupulous and despotic landowners (nobles) of the medieval period in Europe. They hindered commerce by imposing unauthorized tolls and tariffs and at times by sometimes ransoming or hijacking the goods outright of (pack-animal-dependent) caravans and riverine traffic amidst the poorly roaded tracts of the vast and far-flung demesnes of the Holy Roman Empire, in particular. The term has slightly different meanings in different countries, and has changed somewhat over time. In modern U.S. parlance, the term since the mid-nineteenth century had also come to be used to describe unscrupulous industrialists (see robber baron (industrialist)) and stock speculators, who like the Germanic robber barons enriched their own pockets without adding to the common good by adding value.