Tu’i Nayau is the title held by the paramount chief of the Lau Islands in Fiji and is synonymous with the title holders over lordship of these islands. When translated, Tu’i Nayau means "Lord of Nayau", an island north of Lakeba, the latter accepted by many to be the chiefly island in the Lauan archipelago. Prior to being installed as Tu’i Nayau, the claimant must first be confirmed upon the decision of the noble households making up the Vuanirewa clan and then installed Sau or High Chief of Lau. Not every Sau has been installed Tu’i Nayau.
Tu’i Nayau was originally an independent title referring specifically to the of Nayau, then separate from the Lakeba State.
The earliest oral records suggest that the progenitor of the leading family of Nayau stemmed from Tuivanuakula, celebrated chief who had won the infamous Cici Turaga, but was not accepted by his older brothers and relatives as he was the youngest in that race. Tuivanuakula had two sons and a daughter, Buivaroro, Kalouyalewa and Adi Keletu.
The period after the death of Chief Niumataiwalu in Ono-i-Lau can be assumed to have followed with the conquest of Lakeba by the Levuka people from Bau and supplanting the supremacy of the Cekena dynasty in the Lakeba State with a dictatorship under the heavy hand of the Levuka peoples’ leader, Codro. Before this occurred, Niumatawalu’s surviving sons had fled and sought refuge with their relatives.
It was during this exile on Nayau when Rasolo, Niumataiwalu’s son set up his foundations near a rewa (Cerbera manghas) tree. The name Vuanirewa comes into existence. With the passing of Vukinavanua, an ensuing dispute among the nobles over who should succeed him arose. According to oral history, the high priest intervened by taking all claimants to the top towering cliffs called Delaiwawa and indicated that the only one to leap from the cliff and live would be worthy to succeed to the title. It is here that Rasolo enters into the legend, as he is the only one who takes up the challenge, leaps and survives.