A Ngāti Whātua Ōrākei spokesperson said this year marked the 182nd anniversary of the day Te Kawau allocated land to the Crown to establish the city.
"Without that act, Tāmaki Makaurau as we know it may have looked very different to the bustling metropolis it is today."
The city's current anniversary is celebrated in January to mark the arrival of Lieutenant-Governor William Hobson in the Bay of Islands in 1840, which was closely tied with British sovereignty, iwi trust chairwoman Marama Royal said.
"Few people know that Auckland was actually founded in September 1840."
Hence, Ngāti Whātua Ōrākei has called for September 18 to be recognised as the city's true anniversary, and act as a permanent reminder of its origins, "one that has been missing from its historical narrative for nearly two centuries", Royal said.
"Most people have no idea of the real founding of Auckland, instead linking it back to early land speculators like Logan Campbell and acts of legislation.
"But the origins have actually come from an enduring partnership between Ngāti Whātua Ōrākei and the Crown, underpinned by obligations and responsibilities to each other."
Royal said after paramount chief Apihai Te Kawau signed Te Tiriti o Waitangi at Whakarongo Pā in March 1840, he sent envoys to Hobson in Russell with an offer of Ngāti Whātua land to establish the Aotearoa capital on the Waitematā Harbour.
"On September 18, 1840, Apihai Te Kawau formally granted Governor Hobson use of 3000 acres of land, a process called tuku whenua, or land allocation, to establish the settlement.
"Tuku whenua involves granting the use of land for mutual benefit for both the home community and the settler who is granted its use."
Te Kawau enabled the government to gain a footing in Auckland and provide a place for the influx of British immigrants, while Hobson got to relocate the capital from Russell to a more central location with an abundance of land and trading opportunities, Royal said.
"We believe Apihai Te Kawau should also be recognised as a founding father of Tāmaki Makaurau."
The iwi has invited all Aucklanders to join it this year in celebrating the city's 182nd anniversary through live and streamed events across five significant sites on the day.
Ceremonies are set to be held in sequence on Sunday, September 18 starting at 6.30am, finishing at Ōrākei marae at 8.30am.
The sites are: Maungawhau-Mt Eden; Ōpoutūteka - Coxs Head; Taurarua (above Parnell Baths); Te Rerenga Oraiti - Emily Place and Ōrākei Marae. People can follow the proceedings online, with a two-hour live streamed commemoration on the Ngāti Whātua Ōrākei Facebook page from 6.30am.