Anthropologists believe that Polynesians from the Marquesas and Society Islands first populated the Hawaiian Islands approximately 1500 years ago. These first peoples preserved memories of the early migrations orally through genealogies and folk tales, like the stories of Hawai‘iloa and Pa‘ao. Relations with other Polynesian groups were sporadic during the early migratory periods, and Hawai‘i grew from small settlements to a complex society in near isolation. Local chiefs called ali‘i ruled their settlements and fought to extend their sway and defend their communities from predatory rivals. Warfare was endemic. The general trend was towards chiefdoms of increasing size, even encompassing whole islands.