Istwa Nou

Along the trade routes of the Congo basin, and especially where routes met, chiefdoms and small states began to form during the first millennium BCE and the first millennium CE. Commerce produced them. Smiths supplied their rulers with a particular emblem, the flange welded double bell. The two bells were tuned to different pitches, one high and one low. Bantu languages are generally tonal, so any set phrase carries a fixed sequence of high and low tones through its words. The man carrying the bells for a chief could strike them in that sequence and play a saying that asserted political or ritual authority, and everyone within earshot, knowing the phrase, would hear which one it was. Jan Vansina showed from linguistic and archaeological evidence that the double bells were already widespread across the Congo basin during the first millennium CE, and that by the early second millennium they had reached the Zambezi and the country that became Great Zimbabwe.