Frøslevlejren was an internment camp, and Danish accounts are careful to keep that word distinct from the German concentration camps it was created to circumvent. There was no forced labour regime designed to kill, no gas chamber, no systematic starvation. German security police held authority over the perimeter and the guards; a Danish administration handled food and supplies, and Danish sources record that the prisoners suffered no real deprivation in food or health. That is the honest comparison — and it is a comparison, not an exoneration. These were people locked up without trial behind barbed wire and watchtowers, cut off from their families, most of them detained on suspicion of resistance work, communism, or simply the wrong politics. Around twenty escape attempts were made from the camp. Roughly half of them succeeded.

The first 741 prisoners arrived on 13 August 1944, transferred from Horserød in north Zealand. Over the nine months that followed, some 12,000 people passed through the gates — an extraordinary number for a country of four million. By the final weeks of the occupation about 5,500 were being held at once. They were resistance fighters and suspected resistance fighters, communists, political detainees, men swept up in reprisal arrests. Some knew exactly why they were there. Others never learned. What they shared was a specific and unresolvable dread: that a name would be read out, and that the name would go on a train south.

It happened roughly 1,600 times. Despite the agreement that had brought the camp into being, the Germans deported around 1,600 Frøslev prisoners onward to concentration camps inside Germany. About 220 of them died there. Those numbers are the moral centre of the place. Measured one way, the camp worked: more than ten thousand people were held in Denmark who might otherwise have been sent to Neuengamme, and they survived. Measured another way, the bargain was worth exactly as much as the occupier chose to honour, which was not all of it. Two hundred and twenty Danes died in German camps after their own government had negotiated an arrangement meant to prevent precisely that.

In the last spring of the war, rescue arrived from an unlikely direction. The Swedish count Folke Bernadotte, working through the Swedish Red Cross, negotiated to extract Scandinavian prisoners from German camps, while Danish officials pressed in parallel for the return of their own citizens. Convoys of buses painted white, marked with red crosses so Allied aircraft would not strafe them, drove into Germany and drove back out loaded with people. Through March and April 1945 roughly 10,000 Danish and Norwegian prisoners came home. Some were delivered to Frøslev. Among them were men from the 1,960 Danish police officers seized and deported on 19 September 1944 — arrested en masse for the crime of being an unreliable police force.

On 5 May 1945 the Germans left, the prisoners walked out, and within days the barbed wire was pointed the other way. Renamed Fårhuslejren, the camp filled with Danes accused of collaboration — among them Frits Clausen, the physician who had led Denmark's Nazi party. The Danish resistance ran it at first; the state soon took over, and Fårhus became the country's largest facility for convicted collaborators, holding some 4,600 people between 1945 and 1949. Around 3,000 of them came from the German-speaking minority of South Jutland, a fact that left a long bitterness in the border region and complicated the camp's memory for decades. By October 1949 the sentences had largely been served and the camp closed.

It became army barracks under the name Padborglejren, and it could easily have been bulldozed into a footnote. Instead the Frøslev Prison Camp Museum opened in 1969 under the National Museum of Denmark, and a 2001 agreement preserved the whole site as a national memorial. Pieces that had been torn down — a watchtower, a stretch of the barbed-wire fence — were rebuilt so that the geometry of the place would still read. The barracks stand in their rows. A residential folk high school, Frøslevlejrens Efterskole, now occupies part of the grounds, which means teenagers do their homework inside a camp their great-grandparents were imprisoned in. Denmark chose to keep the evidence of its most compromised wartime calculation, rather than the flattering version.