He served as Senior SS and Police Leader (HSSPF) in occupied France, from May 1942 to November 1944, during the Second World War, Oberg came to be known as the Butcher of Paris.

His enlistment was postponed, he then achieved his war Abitur in August 1915 and was subsequently assigned to the artillery, serving as battery officer with Lauenburgisches Feld-Artillerie-Regiment Nr.

[5] On Heydrich's orders, Oberg deported over 40,000 Jews from the country with the assistance of the Vichy France police force headed by René Bousquet.

[6][7][8] On 18 January 1943, Himmler demanded a "cleansing" of Marseilles with 100,000 arrests and explosive demolition of the city's crime district.

Working with the French police, Oberg supervised a lesser response of 6,000 arrests, 20,000 people displaced, and partial destruction of the harbour area.

On 10 April 1958, the sentence was commuted to life by French President Vincent Auriol, whose successor René Coty then reduced it further to 20 years hard labor in 1959.

[2][a] Oberg then was repatriated to Flensburg, in the north of the German state of Schleswig-Holstein, at the time, according to Die Zeit, a stronghold of former Nazis and SS cadres.