The British were able to maintain their power over the Zulu following the Zulu War primarily through their military superiority. After the conflict, which included significant battles such as the Battle of Isandlwana and the Battle of Rorke's Drift, the British were able to exert control over the Zulu Kingdom through their superior military organization, technology, and resources.
After achieving victory in the war, the British dismantled the Zulu political structure, dividing the Zulu territory and instituting colonial administration. This military dominance and the subsequent establishment of direct and indirect governance helped the British maintain control over the region. Therefore, while other factors may have contributed to their ongoing influence, military superiority was the most significant factor in the immediate aftermath of the Zulu War.