Fearing that Ttikanga Māori was going to be lost with so many deaths during the war and from the Spanish flu, Sir Āpirana Ngata initiated the Dominion Museum Ethnological Expeditions in 1919.
The expeditions spanned the North Island documenting moments of cultural significance within the Māori community through film, wax-cylinder recordings and photography.
During WWI 18,000 Kiwis died in two months, quickly followed by 9000 dying from the Spanish flu.
Ngata watched many kaumatua and tohunga, who held a lot of knowledge of Māori culture and practice, die.
He decided something needed to be done to capture the knowledge before it was lost.
He wrote to Internal Affairs asking them to use the technology they had to record and photograph Māori hui.
The first of the recording expeditions was held in Gisborne with the Hui Aroha in April 1919.
The story of these expeditions have been brought to life in the book
Hei Taonga mā ngā Uri Whakatipu, Treasures for the Rising Generation.
One of the authors, Dame Anne Salmond, a professor of Māori Studies and Anthropology at University of Auckland, has a personal connection with the book.
Her great-grandfather was the acting director of the Dominion Museum when Ngata wrote to Internal affairs.
With his expertise in film and photography, her great-grandfather happily obliged.
"The interesting thing about the book is we have people that are descended from the tīpuna in the photos writing about them and talking about them. It's beautiful," Salmond said.
Author and historian Dr Monty Soutar was approached by Salmond to be a part of the book because of his extensive knowledge of the Māori Battalion.
"Monty was a no-brainer because he is the great authority of the battalion," she said.
"He's from Tairāwhiti, so when he wrote that chapter it was perfect."
The Hui Aroha was a planned welcome home to the Māori Battalion from the Eastern Māori Electorate, which was Bay of Plenty through to Hawke's Bay.
The hui included a commemoration and tangi.
As a descendant of Sir Āpirana Ngata, Dr Wayne Ngata also became involved in the book through Salmond, who was a lecturer of his, at the University of Auckland.
Over the past decade, they have collaborated on research and writing about the tīpuna of Tairāwhiti.
When sifting through some of the material that was kept at Āpirana's home in Waiomatatini Ruatoria, Dr Ngata found his part for the book.
"The particular piece that I am interested in and is part of the book, is around the terminology of whakapapa, and how Āpirana brings clarity to it for our generation," he said.
Dr Ngata said the preservation of Māori culture was just as important now.
"Āpirana comments that taonga, Māori culture, kōrero was disappearing fast, and he was very fearful at that time."
"If he was fearful then, we should be far more fearful now."
Natalie Robertson has a connection to Tairāwhiti through her ancestors George Gillespie Boyd and Riria Kawhena.
She became interested in the book through her interest in photography.
She made contact with Salmond about her great-grandfather's photos when she found a convergence between their photography of the Waiapu River in Gisborne.
"I was particularly interested in the Ngāti Porou perspective in the Ethnographic Expeditions rather than the institutional one," Robertson said.
She said the quality of the photos from 100 years ago was remarkably high.
"Their mauri, their wairua, shone through for me and it compressed time and space.
"It felt as if I could be there with our tīpuna and the people of Ngāti Porou."
Other events included in the book are the 1920 welcome to the Prince of Wales in Rotorua, communities along the Whanganui River in 1921 and Tairāwhiti in 1923.
Hei Taonga mā ngā Uri Whakatipu was published by Te Papa Press and is available in bookstores.
For more information on the book click here