Nafanua was a historical aliʻi (Paramount Chief/Queen) and toa (warrior) of Samoa from the Sā Tonumaipeʻa clan, who took the four pāpā (district) titles, the leading aliʻi titles of Samoa. After her death she became a goddess in Polynesian religion.

There are historical and mythological traditions about Nafanua's family and life. She reportedly played a crucial role in the civil wars between the districts of eastern and western Savaiʻi.

According to Samoan mythology, she was the daughter of Saveasiʻuleo, also considered a demigod, the Aliʻi of Pulotu. Pulotu was both a historical place, and a place of the afterlife for the warriors of Samoa (comparable to the Viking concept of Valhalla). In one tradition, Nafanua's mother was Tilafaiga the sister of Taema, the legendary conjoined twins, whom brought the malu tattoo to Samoa.

Nafanua was bestowed the title of Toa/Toa Tamaʻitaʻi (or Warrior Princess) for avenging her uncle and bringing peace to Savaiʻi through military victories. Her village was located on the western side of the island of Savaiʻi.

During Nafanua's time, the eastern and western sides of Savaiʻi were engaged in a war for the land and title of the entire island. In Samoan culture, a family is more prestigious if they own a lot of land; and family members (especially males) receive greater titles and a bigger share of the land. According to oral tradition, when High Chief Lilomaiava caught anyone from the east side on the west side of the island, he would force them to climb a coconut tree upside-down as a public punishment

One of the villagers that Lilomaiava caught was Taʻiʻi, the uncle of Nafanua and the older brother of Saveasiʻuleo. Taʻiʻi was punished and was forced to climb the coconut tree feet first. As he was climbing the coconut tree, the pain and humiliation caused him to sigh loudly. Taʻiʻi's sighs were overheard by Saveasiʻuleo and Nafanua. This made Savesiʻuleo angry; consequently he told Nafanua to prepare for war and to cut down the Toa tree. The wood from the tree was to be used to make weapons to drive away Lilomaiava and his army.^{[citation needed]}

She made the following four weapons from the Toa (also known as Koa) wood. They are as follows:

These weapons are now considered the traditional Samoan weapons, and are used today more so as decorative objects.