[10] Most Nilotic speakers in the area, including the Maasai, the Turkana and the Kalenjin, are pastoralists and have a reputation as fearsome warriors and cattle rustlers.

[14] The Maasai territory reached its largest size in the mid-19th century and covered almost all of the Great Rift Valley and adjacent lands from Mount Marsabit in the north to Dodoma in the south.

[15] At this time the Maasai, as well as the larger Nilotic group they were part of, raised cattle as far east as the Tanga coast in Tanganyika (now mainland Tanzania).

The estimate first put forward by a German lieutenant in what was then northwest Tanganyika, was that 90% of cattle and half of wild animals perished from rinderpest.

These subdivisions are known as 'nations' or 'iloshon' in the Maa language: the Keekonyokie, Ildamat, Purko, Wuasinkishu, Siria, Laitayiok, Loitai, Ilkisonko, Matapato, Dalalekutuk, Ilooldokilani, Ilkaputiei, Moitanik, Ilkirasha, Samburu, Ilchamus, Laikipiak, Loitokitoki, Larusa, Salei, Sirinket and Parakuyo.

[26] The Maasai's autosomal DNA has been examined in a comprehensive study by Tishkoff et al. (2009) on the genetic affiliations of various populations in Africa.

[27] Tishkoff et al. also indicate that: "Many Nilo-Saharan-speaking populations in East Africa, such as the Maasai, show multiple cluster assignments from the Nilo-Saharan [...] and Cushitic [...] AACs, in accord with linguistic evidence of repeated Nilotic assimilation of Cushites over the past 3000 years and with the high frequency of a shared East African–specific mutation associated with lactose tolerance.

[28][29] A 2019 archaeogenetic study sampled ancient remains from Neolithic inhabitants of Tanzania and Kenya, and found them to have strongest affinities with modern Horn of Africa groups.

[30] A Y chromosome study by Wood et al. (2005) tested various Sub-Saharan populations, including 26 Maasai men from Kenya, for paternal lineages.

Some maternal gene flow from North and Northeast Africa was also reported, particularly via the presence of mtDNA haplogroup M lineages in about 12.5% of the Maasai samples.

[39] The "Mountain of God", Ol Doinyo Lengai, is located in northernmost Tanzania and can be seen from Lake Natron in southernmost Kenya.

The central human figure in the Maasai religious system is the laibon whose roles include shamanistic healing, divination and prophecy, and ensuring success in war or adequate rainfall.

[43] A corpse rejected by scavengers is seen as having something wrong with it, and liable to cause social disgrace; therefore, it is not uncommon for bodies to be covered in fat and blood from a slaughtered ox.

[49] One common misconception about the Maasai is that each young man is supposed to kill a lion before he can be circumcised and enter adulthood.

[56][57] Traditionally, the Maasai conduct elaborate rite of passage rituals which include surgical genital mutilation to initiate children into adulthood.

Importantly, any exclamations or unexpected movements on the part of the boy can cause the elder to make a mistake in the delicate and tedious process, which can result in severe lifelong scarring, dysfunction, and pain.

The female rite of passage ritual has recently seen excision replaced in rare instances with a "cutting with words" ceremony involving singing and dancing in its place.

However, despite changes to the law and education drives, the practice remains deeply ingrained, highly valued, and nearly universally practised by members of the culture.

[66][67] Upon reaching the age of 3 "moons", the child is named and the head is shaved clean apart from a tuft of hair, which resembles a cockade, from the nape of the neck to the forehead.

[42] Among the men, warriors are the only members of the Maasai community to wear long hair, which they weave in thinly braided strands.

[91][92] Although consumed as snacks, fruits constitute a major part of the food ingested by children and women looking after cattle as well as morans in the bush.

[98] Maasai traditional clothing is both a means of tribal identification and symbolism: young men, for example, wear black for several months following their circumcision.

[101] Maasai near the coast may wear kikoi, a sarong-like garment that comes in many different colours and textiles[102][103][104] A traditional pastoral lifestyle has become increasingly difficult due to modern outside influences.

Garrett Hardin's article outlining the "tragedy of the commons", as well as Melville Herskovits' "cattle complex" influenced ecologists and policymakers about the harm Maasai pastoralists were causing to savannah rangelands.

[citation needed] In 1975 the Ngorongoro Conservation Area banned cultivation, forcing the tribe to participate in Tanzania's economy.

Lawyers, human rights groups, and activists who brought the matter to light claimed that Tanzanian security forces tried to forcefully evict the indigenous Maasai people from their ancestral land for the establishment of a luxury game reserve by Otterlo Business Corporation (OBC) for the royals ruling the United Arab Emirates.

As of 18 June 2022, approximately 30 Maasai people had been injured and at least one killed, at the hands of the Tanzanian government Field Force Unit (FFU) while protesting the government’s plans of what it claims are delimiting a 1500 sq km of land as a game reserve, an act which violates a 2018 East African Court of Justice (EACJ) injunction on the land dispute, per local activists.

A hunting concession already situated in Loliondo is owned by OBC, a company that has been allegedly linked to the significantly wealthy Emirati royal family as per Tanzanian lawyers, environmentalists as well as human rights activists.

Anuradha Mittal, the executive director of the environmental think-tank, Oakland Institute cited that OBC was not a "safari company for just everyone, it has operations for the royal family".

Meanwhile, the OBC commented on the matter without addressing alleged links with Emirati royals, stating that "there is no eviction in Loliondo" and calling it a "reserve land protected area" owned by the government.