Limitrophe states are territories situated on a border or frontier. In a broad sense, it means border countries — any group of neighbors of a given nation which border each other thus forming a rim around that country. The English term derives from "pays limitrophes", a term in diplomatic French. In ancient Rome, the term referred to provinces at the borders of the Roman Empire (Latin: limitrophus), which were obliged to provide billeting of the limitanei legions deployed on their territory, mostly in limes.