According to the Kalenjinsocial system, the male sex is divided into boys, warriors and elders. The female sex is divided into girls and married women. The first stage began at birth and continued till initiation. All boys who were circumcised together are said to belong to the same ibinda,ipinda or ebendo. These age sets played a significant role in traditional Kalenjin society since they were used to record time. Once the young men of a particular ibindacame of age, they were tasked with protecting the tribal lands and the society, the period when they were in charge of protection of the society was known as the age of that ibinda. There were eight ages in general though this varied between sections as an age-set would temporarily be dropped from use if a disastrous incident occurred during the age of the ibinda. Within each age-set, the initiates were further bundled into a siritiet - what can be understood as a 'team'. The age of an ipinda sometimes acquired a nickname based on a defining event occurring during their time.
– *La Fontaine states there are eight "age classes" but lists seven names, the order of which is questionable.
Marakwet
There are corresponding female age-sets among the Marakwet; for example, Kaberur – Chemeri/ Chemeri Kipchesum, Kaplelach - Tabesit / Tabesit ruompo Laikok, Kipnyikew/ Kipmke - Silingwa, Nyongi - Kaptura, Maina – Charkina, Chumo – Kipturbei, Sowe - Chelyong/ Kapcheusi, Korongoro - Cheptentur/ Sikinkin/ Kesengen. The Marakwet still circumcise girls alongside boys. However, the naming of female age-sets changes according to prevailing events.
Historically, the Nandi had eight cyclical age-sets or ibinwek, however they dropped one for a total of seven. Legend has it that the members of this ibinda were wiped out in war. For fear of a recurrence, the community decided to retire the age-set. The order of Nandi ibinwek is given below.
Maina
Chumo
Sawe
Kipkoimet
Kaplelach
Kipnyigei
Nyongi
Age sub-set (siritiet)
In each age-set, the initiates were bundled into siritiet or what can be understood as a 'team'. There are four 'teams' or siritoik in an ibinda namely:
