The brigade fought against the local soviet republics that arose during the German Revolution of 1918–1919 and later was among the key players in the anti-republican Kapp Putsch of March 1920.

After the brigade's forced disbanding, Ehrhardt used the remnants of his unit to found the Organisation Consul, a secret group that committed numerous politically motivated assassinations.

Ehrhardt was born in 1881 into a family that had long provided pastors for Diersburg (now part of Hohberg, Baden-Württemberg) in the Grand Duchy of Baden.

In the Battle of Jutland, his group participated in the sinking of the British 1,000 ton destroyer HMS Nomad, and his own flagship, the SMS V27 was sunk in action.

When they mutinied in the face of the dangerous mine belt off the German coast and refused to proceed, Ehrhardt forcibly took command and brought the ship safely to port.

[4] After recruitment and training were completed, the brigade received orders in April 1919 to intervene under the command of General Georg Maercker against the attempts to establish a soviet republic in Braunschweig.

Ehrhardt's brigade quelled riots across central Germany and on 30 April 1919 was in place outside of Munich as part of about 30,000 men[5] preparing to attack the Bavarian Soviet Republic.

In June the brigade was deployed in Berlin against a transportation strike and in August in Upper Silesia against the Poles who in the First Silesian Uprising were fighting German control of the region.

Ehrhardt found in Wolfgang Kapp and General Walther von Lüttwitz, at the time commander-in-chief of the Berlin Reichswehr Group Command I, two men who were determined to reverse the results of the revolution.

The Reich government ordered the disbanding of the Marine Brigade Ehrhardt and other Freikorps units in early March 1920 under pressure from the Allies who were overseeing the fulfillment of the terms of the Versailles Peace Treaty.

Lüttwitz placed himself at the head of the Marine Brigade Ehrhardt, which through an influx of wildcat units had grown to between 2,000 and 6,000 men,[5] and occupied Berlin's government quarter.

In the fall of 1920, the rest of the unit formed the Organisation Consul, an underground right-wing organization that used assassinations to try to provoke a coup from the left so that it could then offer its support to the Reich government in fighting it.

[2] In the absence of its leader, the Organisation Consul disintegrated and was banned by the Act for the Protection of the Republic (Gesetz zum Schutze der Republik)[14] on 21 July 1922.

He supported the conservative group around Bavarian State Commissioner Gustav Ritter von Kahr, who wanted a right-wing dictatorship to replace the Weimar Republic, but not one under Adolf Hitler's leadership.

He assembled his troops – consisting mainly of formations of the Viking League – in Upper Franconia and was ready to march against Hitler, but by then the putsch had already failed in Munich.

Hans Ulrich Klintzsch, a lieutenant in the Organisation Consul, became head of the SA, and Alfred Hoffmann, an Ehrhardt man, became chief of staff.

They included journalist Friedrich Wilhelm Heinz, press officer Herbert von Bose and editor Hartmut Plaas.

The historian Armin Mohler pointed to the connections that leading members of the military resistance, such as Admiral Wilhelm Canaris and General Hans Oster, had to Ehrhardt.

[19] On 28 June 1933, the newspaper Westhavelländische Tageszeitung reported that the SS had announced that "Captain Ehrhardt has declared his allegiance to the Nazi Party".