[1] He grew up as part of the aristocracy of the pre-unified kingdom of the island of Hawaiʻi and was a descendant of Paʻao, a lineage that added to his prestige as a spiritual leader.

Hewahewa's great-grandfather was Holoʻae,[note 1] the kahuna of Alapaʻinui and Kalaniʻōpuʻu, the latter of whom ruled during James Cook's fatal visit to the islands.

[8] By the 1810s, Hewahewa was serving as kahuna-nui (high priest) and was responsible for maintaining the kapu code of conduct at the behest of King Kamehameha.

His doubts were reinforced by the efforts of Kaʻahumanu, the late Kamehameha I's favorite wife, who had a relationship with high priest and persuaded him action was needed to break the kapu.

Not all of the native Hawaiian religion was interfered with; family ʻaumākua remained untouched and the kahuna retained much of their political power as scholars and healers.

[16] As an old man, he was called upon by Kamehameha III in an attempt to restore the native Hawaiian faith but Hewahewa persuaded the king to abandon the effort.

[16] According to reports in the contemporaneous Ke Kumu Hawaii and the Sandwich Island Gazette, Hewahewa died on February 16, 1837, at his home in Waimea, Oahu.

[16][17] There is, however, some discrepancy about his date of death; in 1893, Nathaniel Bright Emerson, who was born 1839, remembered Hewahewa "as a silent and wrinkled old man, who lived in a retired valley in Waialua, Island of Oahu, about the year 1848".