Te Kupenga signed the Waitangi sheet of the Treaty of Waitangi on 9 July 1840 in Tāmaki (Auckland), possibly at Karaka Bay. He was a rangatira (chief) from Ngāti Pāoa and lived at Whakatīwai pā near Maraetai on the Hauraki Gulf. He was a brother-in-law of Eruera Maihi Patuone of Ngāpuhi, who signed the treaty on 6 February 1840.
In 1839 Te Kupenga sold an unspecified piece of land to the missionary William Fairburn for 20 blankets, six iron pots, 12 tinder boxes, six spades, six hatchets, six bars of soap, six knives, six plane irons, six fancy pipes, five scissors, two boxes, six shirts, six pairs of trousers, one gown, 90 pounds of tobacco, six adzes, 12 hoes and 12 axes. In 1853 Te Kupenga and Karamū sold Pōnui (Chamberlins Island, between Waiheke and the mainland) to the Crown for £100.