During the Second World War, approximately 40 000 people were arrested or detained by the Germans or the NS authorities. Some of them were released after a short period of time, but tens of thousands spent up to several years in variuos kinds of prisons and camps. Most of them were kept in captivity in Norway, but several thousand were also sent to Germany where many spent the rest of the war years. Many were killed or died of other causes while in captivity.
There were many reasons why people were caught. The Jews were to be killed, while police, officers and students were detained because the Germans regarded them as possible threats in the resistance. The same went for communists. Norwegians who took an active part in the allied armed forces and who were captivated by the Germans were held as ordinary prisoners of war. It could be worse for Norwegian civilians who were caught for resistance and sabotage activities. They were often held in detention in poor conditions in concentration camps and prisons in Germany, and some were executed.