Early in the morning on the 10th May, 1940, Germany attacked the Netherlands. As of the 15th May, 1940, German occupation was declared in the country. Initially, the Germans stayed in the background, however, already in the summer of 1940, the first Anti-Jewish laws were introduced. Step by step Jews got more and more excluded from public life. Antisemitism grew, and it became commonplace, especially among members of the NSB, the Dutch Nazi party, to harass, threaten and provoke Jewish citizens.
The Jewish members of the Olympia box club did not let that pass unnoticed. With Joop Cosman as their leader, they set up a fight club to stand up against the NSB’s harassment.
On the eve of 11th February 1941, the NSB’s military unit, the WA, once again marched across the Blauwbrug (the “blue bridge” that you can see further East, at the other corner of the Opera building) and into the Jewish district, to harass Jewish citizens. They were singing Antisemitic songs as a provocation. Joop Cosman’s Jewish fight club had been hiding at a playground here on Waterlooplein, and jumped out to face the marching WA members. A fierce fight followed, leaving wounded on both slides. One of the WA members, Hendrik Koot, died three days later from his wounds.