Red strangers - Elspeth Huxley

Growing up in Kenya in the early twentieth century, the brothers Matu and Muthegi are raised according to customs that, they are told, have existed since the beginning of the world. But when the 'red' strangers come, sunburned Europeans who seek to colonize their homeland, the lives of the two Kikuyu tribesmen begin to change in dramatic new ways. Soon, their people are overwhelmed by unknown diseases that traditional magic seems powerless to control. And as the strangers move across the land, the tribe rapidly finds itself forced to obey foreign laws that seem at best bizarre, and that at worst entirely contradict the Kikuyu's own ancient ways, rituals and beliefs.