Proper noun
German Autumn
(historical) A set of events in late 1977, revolving around the kidnapping and murder of industrialist Hanns-Martin Schleyer, by the Red Army Faction (RAF), and the hijacking of the Lufthansa aeroplane Landshut by the Popular Front for the Liberation of Palestine (PFLP).
The events in the autumn of 1977 are frequently referred to as Der Deutsche Herbst ("German Autumn"). Source: Internet