When the Nazis heard Mohammed Amin al-Husseini calling for Arabs to “kill the jews wherever you find them,” they knew they had found an ally in their terrible ideology.

Adolf Hitler believed Muslims could be manipulated into being a powerful tool for the Nazis. For the most part, he was wrong, and the majority of Muslims fought against Germany. However a significant number—a whole division—were radicalized through a partnership with virulently anti-Semitic Islamic extremists.

The main such extremist was al-Husseini, Grand Mufti of Jerusalem and the highest ranking Muslim political leader in Palestine. He was virulently anti-Semitic, with a history of organizing aggressive actions against Jewish people in the Middle East. He also regularly broadcast propaganda over Nazi-controlled radio stations.

As Al-Husseini later explained to Hitler, the Arabs had the same enemies as the Nazis: the Jews, English, and Russians. According to the German record of their meeting, Al-Husseini said the Muslims under his sway “were prepared to cooperate with Germany with all their hearts and stood ready to participate in the war, not only negatively by the commission of acts of sabotage and the instigation of revolutions, but also positively by the formation of an Arab Legion.” He was tasked by Hitler with recruiting Bosnian Muslims into what became the 13th Waffen Mountain Division of the SS, the first non-German SS devision.

Such a partnership was at odds with the Nazi narrative of racial purity, of course. Hitler had declared Muslims racially inferior in Mein Kampf, yet he recruited and met with Al-Husseini. Hitler went on to say say that the Mufti seemed “a man with more than one Aryan among his ancestors” and declared him an honorary Aryan. Bosnia’s Muslims were also declared pure Aryan too. It seemed military and political ends trumped genes for Hitler, who warmed to Islam so long as their enemies remained in common.

Al-Husseini meeting Himmler in 1943

Heinrich Himmler, the commander of the SS and one of the chief architects of the Holocaust, also said he had nothing against Islam because it promises followers “heaven if they fight and are killed in action” and that is was “a very practical religion for soldiers.” He saw an opportunity to manipulate that belief. In fact, it was Himmler who suggested to Hitler raising a Muslim SS division in the first place.

But the prospect did make for some odd imagery. Members of the 13th Waffen Mountain Division wore fezzes emblazoned with Nazi insignias, a contradictory mix of Middle Eastern culture and white nationalism. Pictures from the time show SS members with a pamphlet of anti-Semitic propaganda which, judging by the title, framed Jews as the enemy of Islam.

The Waffen Mountain Division of the SS comprised 20,000 troops and mostly fought Communist resistance forces in Bosnia—a key reason the division was formed in the first place. It fought seven other campaigns for the Nazis in the Balkans region, playing an active role in atrocities committed against Jews there. In all, 12,000 of 14,000 Bosnian Jews were murdered by the Nazis and their allies. Ancient synagogues were destroyed, and some Jews were forced to do that very destroying. The last members of the division surrendered to the British in May of 1945. Ten of them were eventually executed for war crimes.