The Mau Mau movement was not held together by an army command structure. It was held together by oaths. Administered in secret ceremonies, the oaths of the Kenya Land and Freedom Army bound members to the movement and to each other in a covenant that was simultaneously political and spiritual.
For the Kikuyu, oaths were among the most sacred acts in their tradition. The British colonial government, when it learned of the ceremonies, was terrified. They banned the oaths, made administering them a capital offence, and conducted mass screenings attempting to identify those who had taken them.
The oaths held anyway.