A system of ceremonial, non-competitive, exchange practiced in Melanesia to establish and reinforce alliances. This exchange system began among the people of the Trobriand Islands of southeast Melanesia, in which permanent contractual partners trade traditional valuables following an established ceremonial pattern and trade route. In this system, described by the British anthropologist Bronislaw Malinowski, only two kinds of articles, traveling in opposite directions around a rough geographical 'ring' several hundred miles in circumference, were exchanged. These were red shell necklaces and white shell bracelets. Kula objects, which sometimes had names and histories attached, were not owned in order to be used but rather to acquire prestige and rank. Malinowski's study of this system was influential in shaping the anthropological concept of reciprocal exchange. The partnerships between men, involving mutual duties and obligations, were permanent and lifelong. The network of relationships based on the kula served to link many tribes by providing allies and communication of material and nonmaterial cultural elements to distant areas.