Umbu Walu Sasar is the apical ancestor of East Sumbanese origin tradition, named for Cape Sasar (Tanjung Sasar), the northern headland where the ancestors of the Sumbanese are said to have come ashore after crossing the sea from an overseas or overland source. From this landfall the founders dispersed across the island and established the ruling clans (kabihu) of the several domains, so that noble lineages of East Sumba trace apical descent to his line. The migration is bound up with the widespread Sumbanese motif of a great bridge or crossing that later broke, severing the island from the ancestral homeland. As with most Sumbanese apical ancestors, he is remembered chiefly through genealogy and through the megalithic tombs (reti) that anchor clan identity to place; the exact form and spelling of his name, and whether he acted alone or with a paired brother, differ among the oral genealogies recorded in the eastern domains.