The insurgents turned to magic to drive out the German colonizers and used it as a unifying force in the rebellion. A spirit medium named KINJIKITILE NGWALE claimed to be possessed by a snake spirit called Hongo.Ngwale began calling himself Bokero and developed a belief that the people of German East Africa had been called upon to eliminate the Germans. German anthropologists recorded that he gave his followers war medicine that would turn German bullets into water. This "war medicine" was in fact water (maji in Kiswahili) mixed with castor oil and millet seeds. Empowered with this new liquid, Bokero's followers began what would become known as the Maji Maji Rebellion.
The Maji Maji Rebellion (German: Maji-Maji-Aufstand), sometimes called the Maji Maji War (swahili: Vita vya Maji Maji, Maji-Maji-Krieg), was an armed rebellion against German colonial rule in German East Africa (modern-day Tanzania). The war was triggered by a German policy designed to force the indigenous population to grow cotton for export, and lasted from 1905 to 1907. The war resulted in 250,000-300,000 total dead, mostly civilians from famine.
This spirit medium told his insurgents to pour the water on their body and during the battle with the German soldiers, German bullets would turn into water and therefore harmless,the people were very excited and this made those who were demoralized and were scared of losing to the Germans to have confidence and volunteered to fight with the German soldiers
You probably know how this ends. The bullets did not turn into water and the Germans killed many rebels. But there is a twist on the ending, although not a happy one. The rebellion continued, and so the Germans starved the people with an engineered famine by using the scorched earth policy.