- September 1941 - a reception camp in Nis, known as the Crveni krst Camp set up. Around 30,000 prisoners would pass through the camp.
- 23 February 1942 – at the Bubanj killing site, around 850 hostages shot, including male Jews and Roma
- 1963 - the monument in the Bubanj memorial park unveiled
As the second largest city in Serbia, Nis was the most important city in the southern part of occupied Serbia. With the arrival of the occupying forces, it became the seat of Feldkommandantur 809, led by Karl Freiherr von Bothmer. Through the Feldkommandantur, the Military Commander’s Administrative Headquarters exercised control over all quisling and collaborator forces in south-eastern Serbia: Nedic's gendarmerie, Kosta Pecanac’s Chetniks, Ljotic’s volunteer squads, and, from 1942, the Bulgarian occupational corps.
The battle against insurgents and the regulation issued by the military authorities in September 1941 led to the formation of the Crveni krst concentration camp, under the administration of the Gestapo from Niš. Around 30,000 people passed through the camp, of whom about 750 were Jews: men were shot, while women and children were taken to the Sajmište camp. Camp detainees who were designated for killing were taken to the execution field at Bubanj.
On 20 October 1941, the quisling forces blocked all five Roma neighbourhoods, i.e. “mahalas” - Stocni trg, Beograd-mahala, Stambol kapija, Cair and Rabadzi-mahala - and arrested all men over the age of 16 they could find. The Roma serf whose task was to walk in front of soldiers, yelled in Serbian “People, wake up and come out”, while yelling in Romani “Run away, wherever you can”. A total of about 370 Roma were arrested. All were taken to the camp at Crveni krst.
The group of Roma who succeeded in avoiding arrest on the 20 October, liaised with the head of Albanian quislings in Kosovo, Xafer Deva, who interceded on behalf of the Roma before the Gestapo in Niš and saw to it that they be released from the camp. They were released in groups, primarily those who worked in factories, but a group of 90 people was, nonetheless, transferred to the penitentiary and shot at Bubanj on the 23 February 1942 with the Jews and other hostages. Yugoslav Communist Party County Committee’s Nis branch reported on that event saying that 850 people were shot that day, 600 of whom from the penitentiary, almost all male Jews, some Gypsies and some of the remaining hostages from the Crveni krst camp.
The Bubanj execution site is one of the major killing sites in occupied Serbia, second only to the that in Jajinci near Belgrade. German forces used it until the end of the war. According to estimates, over 10,000 people were killed there.
In 1950, the first monument in the shape of a pyramid was built on this site, and, in 1963, a memorial complex was developed with new monuments and an amphitheatre for commemorations.