They are the last remaining hunter-gatherer tribe in Africa, living in Northern Tanzania around the central rift Valley and in the neighboring Serengeti Plateau in the shadow of Ngorongoro crater.  The Hadza people, also known as Hadzabe, are believed to be the oldest tribe the world has known. 
Their home range is also close to Oldvai gorge, one of the most important prehistoric sites in the world, where Homo habilis; one of the earliest members of the genus Homo, was discovered to have lived 1.9 million years ago. Archaeological evidence suggests the area has been continuously occupied by hunter-gatherers since at least the beginning of the Later Stone Age about 50,000 years ago. This makes them probably the only tribe on the planet that occupies its ancestral home since their history does not talk about any other home apart from their current location.
The origin of the Hadza is not clear, though their oral history talks of the 4 eras of their evolution. Each era has a different culture and lifestyle. 
According to them, at the beginning of time, the world was inhabited by hairy giants called the AKA-KA'A-NEBEe or GELANEBE, “ancestors”. 
The Akakaanebe did not possess tools or fire; they hunted the game by staring at it and it dropped dead! Then they ate the meat raw. According to their oral history, the Hadza did not build houses but slept under trees, as they do today in the dry season. In older versions of this story, the fire was not used because it was physically impossible in the earth’s primordial state. In another version, the younger Hadza, who have been to school, say the Akakaanebe simply did not know how to make fire.
The Akakaanebe was succeeded by the Tlaatlanebe, who were equally gigantic but without hair. These Hadza ancestors could make fire and used to cook meat, but animals had grown warier of humans and had to be chased and hunted with dogs. The Tlaatlanebe were the first people to use medicines and charms to protect themselves from enemies and initiated the supreme rite. They lived in caves.
The Akakaanebe was succeeded by the Tlaatlanebe, who were equally gigantic but without hair. These Hadza ancestors could make fire and used to cook meat, but animals had grown warier of humans and had to be chased and hunted with dogs. The Tlaatlanebe were the first people to use medicines and charms to protect themselves from enemies and initiated the supreme rite. They lived in caves.
The Tlaatlanebe was succeeded by the Hamakwabe, who were smaller than their predecessors. They invented bows and arrows, and containers for cooking, and mastered the use of fire. They also built houses. The Hamakwabe was the first of the Hadza ancestors to have contact with non-foraging people, with whom they traded for iron to make knives and arrowheads. The Hamakwabe also invented the gambling game called lukuchuko.
The Hamakwabe was succeeded by the Hamaishonebe, or “modern” Hadza, who are the present-day Hadza people. When discussing the Hamaishonebe era, people often mention specific names and places, and can approximately say how many generations ago events occurred.
The Hadza speak a click language that is unrelated to any other language on earth. The language, however, has been mistaken to be related to Khoisan languages due to click consonants. 
Genetic testing indicates that the Hadza may represent one of the primary roots of the human family tree, perhaps more than 100,000 years old.