After qualifying in 1910, Gillies joined the hospital's newly established Ear, Nose, and Throat Department.
When war was declared in 1914, a 32-year-old Gillies volunteered for the Red Cross.
In 1915, he joined a Belgian ambulance unit as a commissioned officer.
While he served in France, Gillies became aware of the many soldiers suffering jaw and facial wounds.
On his return to the United Kingdom, he persuaded the military authorities to establish a specialist ward for facial injuries at Cambridge Military Hospital in Aldershot.
The catastrophic Somme offensive swamped the hospital.
"A stream of wounded, men with half their faces literally blown to pieces, with the skin left hanging in shreds and the jawbones crushed to a pulp that felt like sand under your fingers," Gillies would later write of the experience.
In July 1917, a Queen Mary's Hospital at Sidcup in Kent was opened as a purpose-built facility for soldiers with facial injuries.
Gillies was put in command of the hospital's British section.
He was joined by 38-year-old Major Pickerill, who had taken leave from the University of Otago, where he had helped found its dental school, and took over the New Zealand section.
Pickerill and Gillies enjoyed a 'healthy' rivalry at Sidcup and would later claim credit for developments and techniques pioneered at the hospital.
Both men's work on facial and jaw reconstructions established them as international pioneers of plastic and facial reconstructive surgery.
After the war, the English-born Pickerill, who had emigrated to New Zealand in 1907, returned home.
But with the large numbers of Kiwi servicemen with serious facial and dental injuries, he established Woodside Jaw Hospital in Dunedin.
The spacious home of ironfounder Richard Brinsley in Lovelock Ave, leased by the Red Cross for three years, allowed Pickerill and some of his staff from Sidcup to continue treating wounded.
Pickerill later embarked on independent practice as Australasia's first plastic surgeon, and is remembered for his innovative work in hare lip and cleft palate surgery.
He died at Pinehaven, Upper Hutt, in 1956, aged 77.
Gillies, who continued to perform reconstructive surgery in the UK, was knighted in 1930, before returning to medical service during World War II.
He died in 1960, aged 78.
A blue plaque on the front of his London house today commemorates his life and work.
Source: NZ History
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