Hundreds of years ago, the Twa were partially supplanted by the immigration of a Bantu group, the ancestors of the agriculturalist ethnic group, today known as the Hutus. The Hutu began to clear forests for their permanent settlements. The exact nature of the third major immigration, that of a predominantly pastoralist people known as Tutsi, is highly contested. Oral histories of the Kingdom of Rwanda often trace the origins of the Rwandan people back nearly 10,000 years ago to a legendary king named Gihanga, to whom metalworking and other modernizing technologies are also commonly attributed.