Deteriorating environmental conditions and the dissolution of the Kongo kingdom in the Atlantic region leads to wide-ranging and protracted violence as rival kingdoms compete for natural resources and political dominance. The European demand for slaves encourages this chronic warfare. Portugal contributes to the instability as it clashes with neighboring kingdoms to establish and expand Angola, a small colony at the northwestern tip of the present country of Angola. The eastern savanna witnesses the rise of the Kuba kingdom and the Luba and Lunda empires, three multi-ethnic states with advanced political systems and rich courtly cultures. While the more isolated Kuba kingdom does not have direct contact with European merchants at this time, Lunda rulers actively encourage trade by opening routes to the coast. Territorial expansion southward to the African Copperbelt in present-day Zambia and east toward Lake Tanganyika extends Lunda commercial control over goods and materials from the East African coast and southern interior. To the north, Luba kings consolidate their political and economic control over neighboring peoples.