After a vacancy in the Tu'i Kanokupolu title, she used her status to designate herself successor, reigning on Tongatapu for slightly less than one year starting in perhaps 1792 before being forcibly deposed by her distant relative Tuku’aho.
[7] In an interview by a Spanish sailor years later, Tupoumoheofo claimed to have been a leading participant in an alliance of the Tu’i Kanokupolu lineage that, “set out from Tonga with some 20 large canoes, putting into the ports of Annamoka [Nomuka] and Happai [Ha’apai].
[9] Some surmise that either he lost influence,[10] he obtained a different title, that Mumui and Tuku’aho forced him out, or that Tupoumoheofo herself instigated the change.
He shared ancestry with Tupoumoheofo through Ma’afu’out’itonga, the sixth Tu'i Kanokupolu, but his was of a lesser line.
[12] Tuku’aho, Mumui’s politically ambitious son and then governor of ‘Eua, strongly supported his father’s claim with hopes of securing power for their line.
She, “went to Hihifo, put a ta’ovala mat about her waist, and sat with her back to the koka tree beneath which the installation of the Tu’i Kanokupolu took place.
Its bones were still easily visible in great number half a century later.”[22] As victor in the brief war, Tuku’aho appointed his father Tu’i Kanokupolu.
[23] Tupoumoheofo spent the remainder of her days in Vava’u under the safety of the 'Ulukalala family, which was at odds with Tuku’aho and Mumui.
[24] William Mariner, a British sailor taken in by Finau 'Ulukalala from 1806 to 1810, writes that the assassination was done at the insistence of Tupoumoheofo to avenge her earlier defeat.