Réseau ferré de France (RFF, French: French Rail Network) was a French company which owned and maintained the French national railway network from 1997–2014. The company was formed with the rail assets of SNCF in 1997. Afterwards, the trains were operated by SNCF, the national railway company, but due to European Union Directive 91/440, the French government was required to separate train operations from the railway infrastructure. On 1 January 2015, RFF became SNCF Réseau, the operational assets of SNCF became SNCF Mobilités, and both groups were placed under the control of SNCF.