Detmold used to be the capital of the petty Principality of Lippe that was transformed into a republic in 1918 and merged into the state of North Rhine-Westphalia in 1947. The former state still has its own regional identity and a separate Protestant territorial church. Nowadays, the city of some 75,000 inhabitants is seat of the administrative region of East Westphalia and Lippe (Ostwestfalen-Lippe, or OWL), which is equivalent to the Teutoburg Forest tourism region.
Teutoburg Forest is the name of a low mountain range that begins right on the southwestern borders of the city. It was presumed by 19th century historians to be identic with the saltus Teutoburgiensis of Roman annals, site of a decisive battle between Roman troops commanded by general Publius Quinctilius Varus and a confederation of Teutonic tribes under the leadership of the Cheruscian lord Arminius (whose name was later Germanised to "Hermann") in 9 AD. "Hermann the Cheruscian" was idealised as a German national hero during the 19th century spirit of romantic nationalism. More recently, archeological digs have identified the actual site of the battle, Kalkriese hill, near Osnabrück and Minden.