In the 19th century, theories circulated about the nature of races, which later became values. And despite the fact that within scientific biology, which considered hereditary factors as existence, the ideas of superior and inferior, "pure" and "mixed races", "worthy" and "unworthy" found their way into criminology, these generated in the people the idea that the races could be "superior", and through the control of procreation, an idea widely spread in Europe and the United States, the idea of the "eradication" of the "non-human people" was carried out. hereditary" in Germany after the First World War.

In 1920, Karl Binding and Alfred Hoche demanded that they lead a "ballast existence" and those who were a "burden to society" to be killed. In 1923, the first chair of Racial Hygiene was held in Munich, from which organizations, groups of scientists and influential individuals fought to spread the ideas of racial hygiene, in the Germany of the years between the wars. Which were used by political parties, in particular the Nazis, who with such ideology fanned the flames of growing resentment towards population groups such as Jews or Gypsies.

The German state of Bavaria, in 1926, which introduced the first laws against the Roma, required gypsies to be registered with the authorities and for these to regulate their movements. And in 1929 the government promulgated the Law at the national level.

With the Nazi party in power, laws were created such as the "Law for the prevention of offspring with hereditary defects", the "Law against habitual dangerous criminals" or the "Law for the protection of German blood and honor", by which the power was granted to the authorities to arrest and intern the Roma in prisons and concentration camps.

The "gypsies", whose place in the system was not easy to determine due to their Aryan ancestry, were generally considered "asocial", an "asocial race", for lack of a better criterion. Initially, they were seen as a police problem, but with the racist influence regarding the ideological evaluation of "Gypsies", the position intensified. And with the racial laws "Nürnberger Rassengesetze" of 1935, the gypsies are classified as an "inferior race", so nationality and citizenship laws are abolished.

Since there were ideological contradictions, their persecution was not coordinated as precisely as it was with the Jewish population. An example of this is that in 1943, there were Roma working in the army, the same army that participated in genocide and persecution of the Roma community in different areas of the country. Later, these soldiers were deported to concentration camps, sometimes with medals of honor.

During World War II (1939 - 1945), the Nazi government made use of mobile killing teams, the Einsatzgruppen, with which they murdered large numbers of Roma and Jews throughout the German-occupied territories.

More than 40,000 concentration camps, ghettos, forced labor factories and other places of detention were created in much of Europe where they brought together Jews, Communists, Republican Spaniards, and Rome. The camps were the centers where people were detained or detained without prior trial and forced to do all kinds of forced labor, where mortality was also high, due to malnutrition, hard work and disease. . Some of the concentration camps were Chelmno, Belzec, Sobibor, Auschwitz-Birkenau, and Treblinka.  

Some camps became “Gypsy camps”, where Roma men, women and children were recruited. An example of these is that of Lety in South Bohemia (Czech Republic), or that of the Belzec complex in Poland.

In 1943, a large number of camps were closed, and prisoners were deported to extermination camps, where people were confined with the intent to kill them, to "cleanse the race." More than 15 million people died in the Bergen-Belsen, Sachsenhausen, Buchenwald, Dachau, Mauthausen, and Ravensbrueck concentration camps.