Being the largest ethnic group in Kenya, they have a lot to do with the political and social climate in the land. About four centuries ago, the kikuyu migrated to their present home. This is the slopes of Mount Kenya formerly known by the kikuyu as Kirinyaga. Kirinyaga is where their God ‘Ngai’ lived. He was also known as Mwene Nyaga. The founder of this great tribe was called Gikuyu, according to their traditions. He was instructed to start the tribe by Mwene Nyaga on Kirinyaga. God provided him with a wife, Mumbi and they got nine daughters who make up the nine clans in the group. Kikuyu cultural practices are being eroded by westernization today.
The family initially known as nyumba was joined by other family units to form a mucii. The mucii, a part of a subgroup mbari formed a muhiriga which is a clan. The nine clans in Kikuyu culture were the Achera, Agachiku, Airimu, Ambui, Angare, Anjiru, Angui, Aithaga, and Aitherandu. Kikuyu cultural practices did not allow for them to fully count people, children and livestock. Therefore the clans were ten but only nine were mentioned.
The counsel elders were the ones who sorted out any disputes in the clan. The ones it could not sort out were resolved by the ordeal of the hot knife where one was burnt on the tongue to determine if he was telling the truth. An oath was also taken to determine whether one was telling the truth. Youths were circumcised to graduate them to become warriors.