Maasai culture is centered around a very sophisticated age-set system. The age-set system distinguishes the different stages of male life. After childhood, the first stage of adulthood starts with initiation, after which a male goes through stages of manhood: young man (ilbarnot), warrior (ilmuran), elder (ilmoruak) and retired elder (iltasati). A new age-division (Olporror) is opened every seven years, a successive pair of divisions forming an age-set (Olaji) on a fourteen year cycle. Alternative age-sets form streams which link older and younger men in relations of authority and political affinity. Whilst the entry into age-sets is organised locally, it is the exclusive right of one particular Maasai section - the Keekonyokie Maasai in the north - to celebrate the opening of a new age-set as the first, which ensures that the age-set system is synchronised throughout Maasai society.

The age-set of warriorhood is the time which stands out as been most typically Maasai, also in the Maasai minds. Ask a Maasai elder about the best part of a Maasai life, and he will revel in stories about his time as warrior, about lion hunts and cattle raids with his age-mates, and about the strong sense of unity and sharing amongst each other. Warriors live in their own special camps called emanyatta, together with their sponsors and instructors - elders of the alternate age-set above them - who impart the knowledge that society expect the warriors to have as adults.

Women do not have a strict age-set system, but tend to be identified with the age-set of warriors with whom they danced as unmarried girls. And by their particular ways of interacting with men in the different stages of their adulthood the women reinforce the importance of the age-set system to Maasai society.