The Deutsche Reichsbahn Gesellschaft was the German State Railway Company between 1920 and 1945. It was created from the railways of the individual states of the German Empire following the end of the First World War. Between 1938 and 1945 the DRG also incorporated the Bundesbahn Österreich (BBÖ), the Federal Railway of Austria.
Following the defeat of Nazi Germany the German lines of the DRG were divided between the Deutsche Reichsbahn (DR) (German State Railway, the railway of the German Democratic Republic) and the Deutsche Bundesbahnen (DB) (German Federal Railways, the railways of the Federal Republic of Germany). Following the reunification of Germany in 1990, after several years of reconnecting the two networks, the two State railways were formally reunited in 1994 to create the current German Railway Corporation (Deutsche Bahn AG (DBAG)).
The railway of the inter-war period is nowadays referred to as Deutsche Reichsbahn Gesellschaft (DRG) or the German State Railway Company Limited, to distinguish it from the East German Deutsche Reichsbahn (DR), but at the time of its existence it was normally referred to simply as the Deutsche Reichsbahn.
The Deutsche Bahn AG (German Railway Corporation), also known as DB and DBAG, is Germany's largest train service operator, providing passenger and freight service on Federally owned tracks.
The Deutsche Reichsbahngesellschaft[?] (DRG) [German Imperial Railway Company] was founded around 1920 by uniting the Staats- and Länderbahnen [State and Territorial Railways] which existed in and were operated by small, formerly sovereign territories and kingdoms like Bavaria, Saxony, and Prussia, among others.
The DRG's successors were named Deutsche Bundesbahn[?] (DB) [German Federal Railways] in the West, while the East kept the the old name minus the "Gesellschaft" [Society], naming its railways DeutscheReichsbahn[?] (DR) [German Imperial Railways] (even though the Empire had ceased to exist.)
The Deutsche Bundesbahn or DB (German Federal Railway) was formed as the state railway of the newly established Federal Republic of Germany (FRG) on September 7, 1949 as a successor of the Deutsche Reichsbahn-Gesellschaft.
With the formation of the FRG these successors units of the DRG were reunited, a situation codified by the Bundesbahn-Law (Bundesbahngesetz) that was ratified on December 13 1951.
Contrary to the DeutscheReichsbahn in the GDR, the DB was not subject to reparations, and benefited from the influx of capital through the Marshall Plan.