The disastrous events that led to a huge loss of New Zealand life on a Belgian battlefield one October day 100 years ago are being recalled in an exhibition in Wellington.
Passchendaele - New Zealand's Darkest Day, opens on Wednesday at the Pukeahu National War Memorial Park.
In late July 1917, British commanders began a series of assaults against German forces holding the ridge overlooking the city of Ypres.
The Battle of Passchendaele was to last more than three months and was notable for the scale of casualties on both sides and the muddy quagmire produced by weeks of rain.
On October 12, 1917, in just a few short hours, 843 New Zealand men lost their lives and almost 2000 others were wounded.
Exhibitions manager Ian Wards says New Zealand's solders climbed from their sodden trenches on to the "water-logged, muddy morass of no-man's-land".
"They struggled through water-filled shell holes, past the broken bodies of dead soldiers and shattered equipment towards the German lines," he said.
"The mud made the artillery hard to aim, so they were unable to break German barbed wire or take out their machine gun emplacements."
The audio-visual exhibition portrays the tragic events of that day, and also features letters and military equipment loaned from Wellington families.
Among the exhibits are the camera and bayonet that belonged to Captain George Gradwell, who was a runner between the lines, delivering messages.
His great grandson, Jack Gradwell, said: "In the course of the war, my great-grandad was gassed, had his skull fractured and was buried alive, but he managed to survive."