Flossenbürg concentration camp was a German prison built in 1938 at Flossenbürg, in the Oberpfalz region of Bavaria. In World War II, most of the inmates sent to Flossenbürg, or to one about 100 sub-camps, came from the German-occupied eastern territories. The camp's site was chosen so that the inmates could be used as free labor to quarry the granite found in the nearby hills. The inmates in Flossenbürg were housed in 16 huge wooden barracks, its crematorium was built in a valley straight outside the camp.

By 1945, there were almost 40,000 inmates held in the whole Flossenbürg camp system, including almost 11,000 women. Inmates were made to work in the Flossenbürg camp quarry and in armaments making. Underfeeding, sickness, and overwork was rife among the inmates, and with the harshness of the guards, this treatment killed thousands of inmates. In 1944, Flossenbürg became a training camp for female guards (Aufseherin) who were members of the Waffen-SS. All together, over 500 women were trained in the camp and in time went on to its subcamps or remained in Flossenbürg. Women matrons staffed many Flossenburg subcamps, such as Dresden Ilke Werke, Freiberg, Helmbrechts, Holleischen, Leitmeritz , Mehltheur , Neustadt (near Coburg), Nürnberg-Siemens , Oederan , and Zwodau .

It is estimated that between April of 1944 and April of 1945, more than 1500 death sentences were carried out here. To this end, six new gallows hooks were installed. In the last months the rate of daily executions overtook the capacity of the crematorium. As a solution, the SS began stacking the bodies in piles, drenching them with gasoline, and setting them alight. Incarcerated in what was called the "Bunker," those who had been condemned to death were kept alone in dark rooms with no food for days until they were executed. Amongst the Allied military officers executed here were Special Operations Executive agents:

1944:

• Francois Gerard Michel executed between 1-15 of June
• Gustave Daniel Alfred Biéler, executed September 6

As Germany's defeat loomed, a number of the SOE agents whom the SS had tortured repeatedly in order to extract information, were executed on the same day. The SOE agents hanged on March 29, 1945 were:

• Jack Charles Stanmore Agazarian
• Phillip John Amphlett
• James Frederick Amps
• George William Hedworth Demand
• Roland Dowlen
• Marcel Georges Florent Fox
• Harry Huntington Graham
• Eugene Francis (Levene) Felangue
• James Francis George Menesson
• Brain Dominic Rafferty
• David Whytehead Sibrée
• V. A. Soskice
• Jean Worms

In early April of 1945, as American forces were approaching the camp, the SS executed General Hans Oster, Admiral Wilhelm Canaris, Rev. Dietrich Bonhoeffer, Dr. Karl Sack , Dr. Theodore Struenck and General Friedrich von Rabenau who were involved in the 1944 Adolf Hitler assassination attempt. They then began the forced evacuation of 22,000 inmates, leaving behind only those too sick to walk. On the death march to Dachau, SS guards shot any inmate too sick to keep up. Before they reached Dachau, more than 7,000 inmates had been shot or had collapsed and died. By the time the U.S. Army 90th Infantry Division freed Flossenbürg on April 23, 1945 more than 30,000 inmates had been killed.

The Flossenbürg War Crimes Trial began in Dachau, Germany, on June 12, 1946 and came to an end on January 22, 1947. Forty-six former staff from Flossenbürg concentration camp were tried by an American Military for crimes of murder, torturing, and starving the inmates in their custody. All but five of the defendants were found guilty, fifteen of whom were condemned to death, eleven were given life sentences, and fourteen were jailed for terms of one to thirty years.

• List of subcamps of Flossenbürg