The Holocaust
At the outset of World War II, more than 100,000 Jews were in Belgium, including 55,000 in Antwerp and 35,000 in Brussels, with smaller communities in Ghent , Liege, Arlon, Mons, Charleroi, Namur and Oostende. At least 20,000 were German refugees, who, along with thousands of others, hoped to flee to the United States.
On May 10, 1940,  Germany invaded Belgium, taking just 18 days to put the country under military rule which lasted until liberation in September 1944.
Anti-Jewish measures began in the autumn of 1940 and grew worse over time. The first prohibitions included ritual slaughter and other religious rites. Other discriminatory actions followed with the s prohibiting Jews from certain professions, such as the fields of law and education. By 1941, authorities started to confiscate property, set up curfews and confined Jews to cities. The s ordered Jews to wear yellow badges in early 1942 and, in September of that same year, began rounding them up by the thousands and deporting them, mostly to Auschwitz. Very few Belgian Jews survived concentration camps.
An active resistance movement, supported by both Jews and non-Jews prevented a higher death toll. The exiled Belgian goverent, as well as the Catholic Church and the Belgian populace, still upset by the German occupation in World War I, resisted a second German occupation. A higher proportion of Jews were saved in Belgium than most other occupied countries. Initially, when the Germans had trouble identifying Jews because the Belgian constitution does not permit mention of religion on civil documents, most Belgians never assisted. In fact, many actually helped Jews. Christian families hid Jewish children and usually honored their requests against baptism. And after the war, almost all Jewish children were returned to their families. In 1942, the s had difficulty finding Belgian police officers to help them put yellow badges on Jews.
The largest Jewish movement, the Committee for Jewish Defense (CJD), affiliated with the national Belgian resistance movement, worked on several levels. The organization hid Jews, fought as partisans, forged identity papers and food ration tickets, obtained funds and set up escape routes. In the cultural realm, CJD distributed information and propaganda material, established a lending library, and maintained a Jewish press, printing in Yiddish, French and Flemish.
Ultimately, the Belgian resistance was not strong enough to fend off the s and their collaborators. Between 1942-44, more than 25,000 Belgian Jews perished in the Holocaust.
*source: jewishvirtuallibrary.org