Maasai are of Nilotic origin, they come from upper Nile valley, they speak maa.
There is many tribes of Nilotic descend other then the Maasai, as the Dinka, Nuer and Sillhuk in South Sudan, the Turkana, Samburu, Luo, Ndorobo and Kalenji in Kenya and Barabaig in Tanzania
Maasai all over east Africa believe and worship only one god called Engaai, they have a sacred mountain called Oldonyo lengaai, the last active volcano in Tanzania, that means the mountain of god.
As a worshipping place the mostly use a species of tree, the strangler fig, oreteti in maa, that is considered a door to reach god. If there is not oreteti in the area, another tree is chosen
They believe that all the cows were given to them as a gift from god and this make raiding other tribes cow an honorable act as they are just recovering what is their by right.
The maasai tribe is divided in various sub tribes : Keekonyokie (North of Natron area between Kenya and Tanzania), Damat (Maasai mara in Kenya), Purko (Ololosokwan, Loliondo areas in Tanzania and Narok in Kenya), Wuasinkishu (Kenya) Moitanik, (Kenya), Siria (Kenya), Laitayiok (Loliondo area in Tanzania), Loitai (Betweeen Loliondo and Pyaia in Tanzania), Kisongo (from Pyaya to Ngorongoro), Larussa (Arusha, Tarangire and Simajiro area), Matapato (Longido area in Tanzania), Dalalekutuk (Kenya), Loodokolani (Shompole area in Kenya), Salei (Pyaia and Endulen in Tanzania) and Kaputiei (Kenya)
Inside every subtribe there are different clans
The most important figures in the maasai society are the leguanans and the liabon.
The leguanans are democratically chosen by their future subjects, each subtribe has its leguanan, each clan has his leguanan, each rika has one or two leguanans, and the rika’s leguanans stay even when the rika passes from warriors to elders.
The liabon is the spiritual and medicine man, leads the community in all religious matters, divines to give the right advice and prescribes potions and herbs to cure diseases and other bad situations. He is not chosen democratically but trough blood lineage where his father was a liabon before him
When they die nowadays there are buried but traditionally were just left in the bush to be disposed by wild animals. If after some days the body was not yet eaten they would slaughter a cow to attract more predators and scavengers