With the Pioneers in France.

In February, 1916, when the Maoris were reorganised for service in France, and were constituted a Pioneer Battalion, under Major G. H. King, Captain Buck was appointed second in command, and now became a combatant officer, Captain H. M. Buchanan (from the Otago M.R.) taking his place as medical officer. Major King was promoted to Colonel and Captain Buck to Major.

Thenceforth the Maoris' work was trench-digging on the Western Front, with now and again a raiding party by way of relief from the trying trench labour under heavy artillery fire. The story of that long and harassing service of the Maoris until the Armistice is told in full in the official history “The Maoris in the Great War.” Heavy shelling was the daily and nightly experience, for month after month. There was a constant drain of casualties.