 As descendants of Tanzania's aboriginal hunter-gatherer population, they have probably occupied their current territory for thousands of years, with relatively little modification to their basic way of life until the past hundred years.Since the 18th century, the Hadza have come into increasing contact with farming and herding people entering Hadzaland and its vicinity; the interactions were often hostile and caused population decline in the late 19th century.The first European contact and written accounts of the Hadza are from the late 19th century.