It must have been a huge blow for the English-born Greenhough who was desperate to "do his duty".
In July 1916, after a period of convalescence in Rotorua, he was discharged from the NZEF.
He tried re-enlisting but was turned down on the grounds of his mature years. But he was thrown a lifeline when he was posted south to become adjutant for the Otago Field Artillery for the rest of the war.
After the war he was heavily involved with the Auckland RSA.
During the construction of the Auckland War Memorial Museum, the RSA campaigned hard for dedicated memorials to the local men and women who died during The Great War of 1914-18.
The top floor of the museum is dedicated to the memory of fallen soldiers with a World War I Hall of Memories.
A roll of honour listing more than 7000 names of servicemen and women who registered in the Auckland province and died in the war is engraved in white Sicilian marble slabs on the sanctuary's wall, encircling the top floor.
Major P. B. Greenhough spent a year painstakingly hand-writing a more detailed roll of honour. Two large leather-bound volumes on either side of the altar contain each Christian name, regimental number, unit, rank, honours, and next of kin.
Greenhough completed his mammoth task in 1932 but died a year later, aged 62, according to Rose Young, history curator at the museum.
"He had finished his work, in his beautiful handscript, but died before it was actually handed over to the museum in 1939," she said. "It's a beautiful piece of work." NZME.
