During the Nazi era, Epp, who had participated in the Herero and Namaqua genocide as a young man, shared responsibility for the liquidation of virtually all Bavarian Jews and Romas as the governor of Bavaria.

He served as a volunteer in East Asia during the Boxer Rebellion in 1900–01 and then became a company commander in the colony of German South-West Africa (now Namibia), where he took part in the bloody Herero and Namaqua Genocide.

[2][3] During the First World War, he served as the commanding officer of the Royal Bavarian Infantry Lifeguards Regiment in France, Serbia, Romania, and at the Isonzo front.

He was also knighted, being made Ritter von Epp on 25 February 1918, and received the Bavarian Military Order of Max Joseph (23 June 1916).

As the SA expanded, it became an armed band of several hundred thousand men, whose function was to guard Nazi rallies and disrupt those of other political parties.

Epp's final notable historical action occurred on 9 March 1933, two weeks before the Reichstag passed the Enabling Act, which granted Hitler dictatorial powers.

[8] Epp was arrested on Paul Giesler's orders in April 1945, for being associated with the Freiheitsaktion Bayern, an anti-Nazi group led by Rupprecht Gerngroß.

On 9 May 1945, a clerk at the hospital alerted agents from the US Counterintelligence Corps that Epp was a patient there, and he was arrested and sent to a prison camp in Munich to await trial at Nuremberg.