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The Duchy of Brunswick Football Association (German: Fußballbund für das Herzogtum Braunschweig) was founded in May 1904 as the first governing body for football in the territory of Brunswick. Previously, clubs from Brunswick had only been able to play friendly matches. Eintracht Braunschweig's chairman Johannes Runge had been the driving force behind the creation of the new association. League play started with the 1904–05 season. During its first season, the champions of the newly founded 1. Spielklasse Herzogtum Braunschweig qualified directly for the German football championship play-off.
In 1905, the Northern German Football Association was founded, and the Duchy of Brunswick Football Association became one of several district associations within the Northern German FA. However, the Brunswick football championship continued to be played as a first tier league, its champions now qualifying for the Northern German football championship, which in turn served as a qualifier for the German championship.
In 1913–14 the league was played as a second tier competition after the introduction of the short-lived Verbandsliga Norddeutschland, a new first tier league that covered all of Northern Germany. Eintracht Braunschweig was the only club from the Duchy of Brunswick that qualified for the new league. However, due to the outbreak of World War I only one season of the Verbandsliga was ever played. In 1920, the new Südkreisliga was created as the new top division of football in the eastern part of today's Lower Saxony, covering Brunswick, the city state of Bremen, as well as the Province of Hanover. Just one season later, however, the Südkreisliga (later renamed Oberliga Südhannover/Braunschweig) was reformed again, this time covering a smaller area including Brunswick and the southern part of Hanover.
^ Horst Bläsig/Alex Leppert, Ein Roter Löwe auf der Brust - Die Geschichte von Eintracht Braunschweig (2010) (in German), publisher: Die Werkstatt, page: 397
Fußball in der Region Braunschweig. 60 Jahre NFV-Bezirk Braunschweig (2006) (in German), publisher: NFV-Bezirk Braunschweig, page: 12
Stefan Peters, Eintracht Braunschweig. Die Chronik (1998) (in German), publisher: Agon-Sportverlag, page: 22
Stefan Peters, Eintracht Braunschweig. Die Chronik (1998) (in German), publisher: Agon-Sportverlag, page: 23
Fußball in der Region Braunschweig. 60 Jahre NFV-Bezirk Braunschweig (2006) (in German), publisher: NFV-Bezirk Braunschweig, pages: 15–16
^ Fußball in der Region Braunschweig. 60 Jahre NFV-Bezirk Braunschweig (2006) (in German), publisher: NFV-Bezirk Braunschweig, page: 15