The history of this single track line along the valley of the Cher is linked with the grand strategy of the Compagnie des Chemins de fer de Paris-Orléans ("P.O."). Contrary to the impression given by its name, this railway company had grands ambitions to extend its tracks all over western and southern France, reaching out first to industrial sites, mines. During the 19th century, the arch enemy of the P.O. was the P.L.M. which had been given the more favourable routes to the south of France via Dijon, Lyon and Clermont-Ferrand. This left the P.O. with the task of crossing the obstacle of the Massif Central.
The railway line from Paris-Austerlitz to Orléans ( Les Aubrais) was opened in 1843, and from Orléans to Vierzon and Bourges in 1847.
The P.O. then wished to grasp the traffic from the industrial region of Montluçon and applied for a line to be established from St-Florent-sur-Cher to Montluçon. North of St-Florent the line was connected to the Vierzon-Bourges route by a triangle allowing trains from Paris and Vierzon to join the line south along the Cher without having to reverse at Bourges.