The Bebra–Baunatal-Guntershausen railway is a two-track, electrified main line in the German state of Hesse, connecting Kassel with Bebra and Gerstungen on the border with Thuringia, as well as with Bad Karlshafen (formerly) and Warburg on the border with Westphalia. It was originally part of the Friedrich-Wilhelms-Nordbahn ("Frederick William Northern Railway"), which was completed in 1849. It was one of the first railway lines in the Electorate of Hesse and in Germany. Route The Frederick William Northern Railway was built by the Frederick William Northern Railway Company (Friedrich-Wilhelms-Nordbahn-Gesellschaft) and named after Frederick William, the Elector of Hesse. It was part of a continuous east-west rail link built between Westphalia and Halle. In Kassel it connected with it the Carl Railway (Carl Bahn), running to the north, which in turn connected in Hümme with the line to Warburg and Westphalia. In Gerstungen it connected with the line of the Thuringian Railway Company. In Warburg it connected to the Hamm–Warburg line of the Royal Westphalian Railway Company. Formation The states of Saxe-Weimar-Eisenach, Saxe-Coburg and Gotha, Prussia and the Electorate of Hesse negotiated from 1840 on the building of an east-west railway. Between Gerstungen in the east of Hesse-Kassel and Haueda (near Liebenau) on the border with Westphalia, the route runs through Bebra and Kassel, then capital of Hesse-Kassel. An agreement was reached in the autumn of 1841. In 1844 the Frederick William Northern Railway Company received a concession to build the line in Hesse-Kassel. Name The line was renamed the Electoral Frederick William Northern Railway (Kurfürst-Friedrich-Wilhelms-Nordbahn) in 1853 and after the annexation of Hesse-Kassel by Prussia as a result of the Austro-Prussian War in 1866 it was renamed Hessian Northern Railway (Hessische Nordbahn). The name Frederick William Northern Railway is not only applied to the line between Kassel and Bebra, but also to the whole route between Warburg and Gerstungen. The first line built in the Electorate was the Carl Railway, the line between Kassel and the Weser river port of Carlshafen (now Bad Karlshafen) then considered the most important line to be built in the state. Subsequently, the two links to Warburg and Gerstungen were added to create the Frederick William Northern Railway. It soon became apparent, however, that the expected traffic to Carlshafen would not eventuate, as traffic quickly moved from the Weser to the emerging rail network. The line to Carlshafen soon became a line of only local significance.