European countries tried to possess territories in Africa and sliced up the region into different colonies. In 1885, Maasailand was cut into half with an international boundary between British Kenya and German Tanganyika.
Subsequently, grazing lands were taken over for white settlement and the Maasais were pushed into a small area in South Kenya and North Tanganyika. The Maasais lost about 60% of their pre-colonial lands. Encouragement was given by the British Colonial Government in East Africa to peasant communities to expand cultivation and pasture lands were converted into cultivated fields.
Large areas of grazing land were also turned into game reserves like the Maasai Mara and Samburu National Park in Kenya and Serengeti Park in Tanzania. Pastoralists were not allowed to enter these reserves.
They could neither hunt animals nor graze herds in these areas. Very often these reserves were in areas that had traditionally been regular grazing grounds for Maasai herds.