It was created at the timetable change in December 2002 as an extension to Duisburg of the Mönchengladbach–Aachen section of the Grenzlandbahn ("border land railway"), which until then had started in Mönchengladbach, where it connected with the Rhein-Emscher-Express, and run via Aachen over the Cologne–Aachen railway to Köln Messe/Deutz station as route RB 21.

The 1998 transport plan of the state of North Rhine-Westphalia and the resolution adopting it provided for the renaming of the Rhine-Nier-Bahn.

On 1 March 2008, the AVV published the Zukunftskonzept 2015 (future concept 2015), which envisaged the Rhein-Niers-Bahn (RB 33) being operated from both Duisburg and Mönchengladbach and Heinsberg to Aachen via Lindern.

[2] The final plans ultimately provided for portion working, in which two units of class 425 sets running from Aachen in double traction would be uncoupled.

However, the stop at Kohlscheid station was restored at the timetable change on 13 December 2015 at the request of many customers.