Due in part to their semi-nomadic and isolationist lifestyle, and differences in language and culture, there has been a great deal of mutual distrust between the Roma and the more settled indigenous inhabitants of the areas to which the Roma migrated. This distrust has persisted even though Roma who migrated into Europe often converted to Christianity, and those who arrived in the Middle East became Muslims.
Persecution of Roma reached a peak during World War II in the Porajmos, the Nazigenocide of Roma during the Holocaust. Because the Romani communities of Eastern Europe were less organized than the Jewish communities, it is more difficult to assess the actual number of victims though the U.S. Holocaust Memorial Research Institute in Washington puts the number of Romani lives lost by 1945 at between a half and one and a half million. The ethnic studies professor Ward Churchill has argued that the Roma population suffered proportionally more genocide than the Jewish population of Europe.
Antizigan discrimination has continued in the 2000s, particularly in the Balkans, in areas such as Bulgaria, Romania and Slovakia. Roma tend to live in low-class ghettos, are subject to discrimination in jobs and schools, and are often subject to police brutality. In spite of long waiting time for a child adoption, Romani children from orphanages are almost never adopted by Czech couples.