They are an abundant significant group in originating in southwestern Arusha and Manyara regions of Tanzania , near the Rift Valley. The Iraqw people settled in the southeast of Ngorongoro Crater in northern Karatu District , Arusha Region, where they remain the majority ethnic group. The Iraqw have traditionally been viewed as remnants of Afro-Asiatic peoples who practiced agriculture and animal husbandry in the Great Lakes region [3] β a succession of societies collectively known as the Stone Bowl cultural complex.
In the Kerio Valley of Kenya , among other neighboring areas, there are vestiges of the Neolithic tillers' civilization in the form of elaborate irrigation systems. Although these particular structures are today maintained by the Marakwet subgroup of the Nandi Kalenjin Nilotes , the latter aver that they were the work of a northern people of peculiar language called the Sirikwa , who were later decimated by pestilence. According to the Marakwet, the Sirikwa "built the furrows, but they did not teach us how to build them; we only know how to keep them as they are.
Additionally, the Iraqw's ancestors are often credited with having constructed the sprawling Engaruka complex in Monduli District , Arusha Region, Tanzania. The modern Iraqw practice an intensive form of self-contained agriculture that bears a remarkable similarity to the ruins of stone-walled canals , dams and furrows that are found at Engaruka. Iraqw historical traditions likewise relate that their last significant migration to their present area of inhabitation occurred about two or three centuries ago after conflicts with the Barbaig sub-group of the Datog Nilotes, herders who are known to have occupied the Crater Highlands above Engaruka prior to the arrival of the Maasai.
This population movement is reportedly consistent with the date of the Engaruka site's desertion, which is estimated at somewhere between and It also roughly coincides with the start of the diminishment of the Engaruka River's flow as well as those of other streams descending from the Ngorongoro highlands ; water sources around which Engaruka's irrigation practices were centered. According to the Maasai Nilotes , who are the present-day occupants of Engaruka, the Iraqw also already inhabited the site when their own ancestors first entered the region during the 18th century.
In , the Iraqw population was estimated to number around , individuals. It has long been known for its intensive cultivation, and referred to as an "island" within a matrix of less intensive cultivation.
