The diaries go into detail of the campaigns William Motion was involved in and what he was doing on each particular day. He enlisted soon after war was announced and spent some months in the trenches at the Suez Canal before being shipped to Gallipoli on April 25 at 4pm, landing under heavy fire.
His entry for the 26th reads simply: "Heavy fighting all day. We were on reserve and remained in the trenches."
The entry for the 27th continues: "We changed position and went out on the left flank. Heavy fire all day. I got my rifle smashed up by shrapnel from a shell."
Other entries tell a story of charging and retreating, digging trenches and suffering from hunger.
On August 8, William Motion was promoted to Sergeant and five days later, he was ordered to hospital and shipped back to Birmingham.
He continued in the Army and was involved in Passchendaele, but not on the front line. William Motion was invalided back to New Zealand in 1918 after suffering trench fever. He became an engine driver on the old steam trains in Otago.
Mr Motion said while his father's diaries talked of his life in the war, all the experiences he shared with his children were of the lighter side of war.
"He did talk about how the stench was terrible and he talked about the flies. And the food, they lived on jam and biscuits."
Mr Motion said his father lived until he was 87 and he was "a great guy".
"He became a St John Ambulance man, he was most interested in that. He was in there for years as a volunteer.
"I'm the youngest of four brothers. In our days as young people, we all sat at the table for meals. Dad would bring up a subject and the brothers would then debate it. It was good like that."
Mr Motion visited Gallipoli about six years ago and was taken for a day long tour of the site by a Turkish man named AJ who had an Australian wife.
His daughter will travel to Turkey for the 100th anniversary of the Gallipoli landings.
