In the first years after the Nazis took power in 1933, the policy towards the Gypsies was an integral part of the new regime's radical social and criminal policies. The centralisation of the Nazi police force and the shift in police priorities from political and social enemies to a biological concept of crime prevention among the people's “racial” enemies came about simultaneously with a more radicalised “Gypsy policy”. Once he had established the Eugenic and Population Biological Research Centre in 1936, Robert Ritter and his colleagues initiated the systematic registration of the country's Roma and Sinti, concluding that over 90 per cent of them were “mixed-breed Gypsies” with asocial and criminal traits that were inextricably linked to their genetic material.
During the course of the war, Roma in most of the German-occupied countries were gradually subjected in one way or another to Nazi persecution and, eventually, to genocide. On 16 December 1942 Heinrich Himmler, head of the SS, ordered the deportation of all German “Gypsies”. Shortly after, the SS formed a separate section for the group in Auschwitz II (Birkenau) extermination camp, the largest of the three main camps in the Auschwitz-Birkenau complex. In the course of the war, more than 23,000 Roma were deported to this camp, which came to be known as Zigeunerlager (Gypsy Camp). Tens of thousands of Roma were also executed by mobile death squadrons and local collaborators on the Eastern Front and in the Balkans. The Gypsy Camp was closed down on the night of 2 August 1944, and only around 2,000 of the deported Roma survived the war.
The order to deport “Gypsy-like individuals” from occupied Belgium and the Netherlands was issued on 29 March 1943, though the mass arrests did not start until the autumn of that year. However, three Norwegian Roma were arrested along with a small group of Belgian Roma as early as February 1943 and arrived at the Gypsy Camp in November 1943. Heinrich Modis was 16 years old when he became one of the first Norwegian Roma to be registered on entry to the Gypsy Camp along with his father Henri and uncle Thorvald. According to the register, Heinrich's father died at the end of that year, before the mass deportation from the Kazerne Dossin internment camp in Mechelen to the Gypsy Camp was carried out on 17 January 1944.
Sixty-two Norwegian Roma were among the 351 deportees on the so-called Transport Z from Mechelen, including Heinrich Modis' mother Lina Russolino Modis and several other family members. Many members of the Karoli and Josef families were also registered as prisoners in the Gypsy Camp that same day. The Karoli family was the first Roma family to be arrested in Belgium, when 19 of them were stopped by the German gendarme in Tournai on 22 October 1943. After internment in Belgium, they were forced on board the train on 15 January 1944 and arrived at Auschwitz two days later. By the end of the year, only two of the deported family members were still alive.