Most of Sub-Saharan Africa was inhabited by settled agricultural, pastoral and iron-using societies over 2000 years ago. These African communities were involved in intercontinental trading systems for a very long time. Beginning in the early 1500s CE, European and colonial American oceanic slave traders began to acquire captives from African powers along the West African coast and shipped them across the Atlantic where they worked (often to death) the plantation economy of the "New World." Around the same time, seafaring Portuguese pushed into the Indian Ocean where they displaced Arab merchant sailors as carriers of regional goods and dominated parts of the East African coast. Before around 1880, most African people lived in independent and diverse societies ranging from highly centralized kingdoms such as Buganda in East Africa to decentralized communities such as those of the Igbo in West Africa.