The population of the Chathams doubled yesterday as more than 700 guests gathered for the official opening of the first Moriori marae, which it is hoped may be used as a centre for peace studies.

Dignitaries and Moriori descendants visiting the island - known to Moriori as Rekohu - from as far as London and New York braved gales as they entered the albatross-shaped Kopinga Marae, perched on a barren hilltop overlooking a glittering bay and fringed with white feathers to mark the blessing ceremony.

At the centre of the five-sided wharenui, or meeting house, stands an enormous potokomanawa, or pole of the heart, on which the names of all Moriori living on the island in 1835 - when it was invaded by Taranaki Maori - have been inscribed.

Standing before the pou, elder Wilfred Davis paid tribute to his great-grandmother, whose name is on the pole and who was taken from the island and forced to live in exile.

Hokotehi Moriori Trust chairman Maui Solomon told the gathering that the Moriori renaissance began in 1980 with the screening of a Barry Saunders television documentary.

It was built on by Michael King's book on Moriori and the Waitangi Tribunal claim that was reported in 2001.

The birth of the $4 million marae heralded a "new beginning not just for Moriori but the Chathams as a whole", he said.

It was hoped the marae would provide a centre for further exploration of Moriori cultural identity and that it could also be used as a centre for peace studies "or perhaps as a place where conflicts can be resolved".

Moriori believe this would be appropriate, as it would reflect the philosophies of their ancestor Nunuku who, 500 years ago, initiated a covenant of peace that allowed Moriori to duel but required them to stop as soon as blood was drawn.

This was last renewed when Taranaki iwi Ngati Tama and Ngati Mutunga invaded and killed many Moriori or consigned them to slavery, decimating their population and resulting in the widespread myth that they were extinct.

"When faced with the greatest challenge to their spiritual belief they did not falter," said Mr Solomon, before turning to the pou: "Your sacrifice wasn't in vain."

Prime Minister Helen Clark told the crowd the peaceful philosophy of thetchakethenu (the people of Rekohu) stood out.

"We acknowledge today the Moriori ancestors and we acknowledge the legacy of peace for which they sacrificed so much."

The Prime Minister said the design of the building was inspired by the ancestors and captured the essence of the Moriori.

Michael King's daughter and son, Rachel and Jonathan, who were among the the guests, presented a picture of their father and his late wife to the marae.

Also present for the ceremonies were the Maori Queen, Dame Te Atairangikaahu, Tuwharetoa paramount chief Tumu te Heuheu, Chief Justice Dame Sian Elias and Maori Party co-leader Tariana Turia.