George Bernard Knight and Herbert Augustine Knight served in the Otago Infantry Battalion and William Douglas Knight served with the Auckland Infantry Battalion.
Their mother wrote them often and made her fears for them clear in one letter penned to George shortly after he enlisted.
"I tried to write last night. I had to tell Dad I could not face it alone. I had a good blub and feel better.
"It will be very hard to part with any of you and I dare say it will mean the three of you," she wrote.
Tragically, her fears came to pass over the course of the war. Her boys were all killed in action, Herbert at Gallipoli and William and George in France.
The Knight story is told in Ngā Tapuwae's Passchendaele Trail, which explores the battle that caused the deaths of 843 New Zealanders on October, 12, 1917.
Ngā Tapuwae New Zealand First World War Trails is an interactive digital experience which guides people through historic landscapes and sites of significance to New Zealanders.
The first blow to the Knight family came on May 8, 1915, when Herbert was shot and killed by a sniper at Gallipoli.
"He was shot through the heart and so suffered no pain, death being instantaneous. It was as great a shock to me as it would be to you," George wrote to his family.
George continued to serve and in 1917 was eager to participate in the Battle of Passchendaele.
"I have been looking forward to this for ever so long . . . as for coming through safely, it is in someone else's hands," he wrote.
The attack on October 12, 1917, was a disaster, with more than 3700 New Zealand casualties and 843 deaths, including that of George.
On New Zealand's darkest day, his luck ran out. Leading his men over the top, up Bellevue Spur, towards the small village of Passchendaele, the 23-year-old company commander encountered impenetrable German barbed-wire defences that the artillery barrage had failed to nullify.
George was cut down by a burst of machine-gun fire only feet from the enemy positions.
His body was never recovered.
George's military service record states: "Many of these men were buried by stretcher bearers where they fell, to right and left of road beyond Waterloo Farm across Ravebeek and up towards crossroads."
A Wanganui Collegiate obituary paid tribute to "a soldier and a gentleman" who was trusted and loved by his men.
He was one of 846 New Zealanders killed at Passchendaele that day. The total number of casualties, wounded, dead and missing, topped 3700.
The day was quickly cemented as one of the bleakest in New Zealand's history.
The next day Douglas embarked from Wellington, not finding out about George's death until he arrived in London.
In a letter home to his family for Christmas 1917, Douglas' grief was evident.
"This is indeed another sad Christmas for us all; sad to me to think how our dear George's death has left you all and how you must be thinking of my fate too, but we must all try to be as brave as possible and hope for the best, but your faith must be almost gone now and mine is not too firm either," he wrote.
Douglas went on to take part in the successful capture of Bapaume, but during the second attack on Bancourt Ridge on September 1, 1918, he was one of 34 men who lost their lives, dying from machine-gun fire.
One of Douglas' letters to his mother, Ellen, arrived after news of his death.
She never opened it.
• Explore more of New Zealand's World War I story at ngatapuwae.nz
Passchendaele - An evening of remembrance
• The Dannevirke World War I committee will host a free event to commemorate our fallen at Passchendaele on Wednesday, October 11, at 7.30pm, in the Fountain Theatre. The evening will include:
• A short movie.
• A speech by Charlotte Descamps, a Passchendaele expert. Charlotte has run tours of the World War I battlefields of Passchendaele and surrounding areas and worked as a guide on the Memorial Passchendaele Museum for many years. She has lived most of her life at Ypres Salient and is a founding member of the Passchendaele Society.
• A display focusing on local servicemen.
• Supper provided.
