Enlisted, appointed to rank of lieutenant, taken on strength Canterbury Infantry Battalion and posted to 13th (North Canterbury) Company, 13 August 1914.
Reported wounded in action, the Dardanelles, 6 June 1915.
Promoted to rank of captain, the Dardanelles, 9 August 1915.
Transferred to Auckland Infantry Battalion with temporary rank of major, the Dardanelles, 11 August 1915.
Promoted to rank of lieutenant-colonel, 2nd Battalion, Canterbury Infantry Regiment, Egypt, 27 February 1916.
Awarded Croix de Guerre (French), 31 May 1917.
Reported wounded in action, 6 June 1917, France; admitted 4th London General Hospital, England, 10 June 1917 (shrapnel wounds, multiple).
Awarded Distinguished Service Order (DSO) for distinguished service in the field, 15 June 1917.
Appointed to command 2nd New Zealand Infantry Brigade, France, 22 December 1917.
Mentioned in despatches by Field-Marshal Sir Douglas Haig for distinguished and gallant service in the field, 31 December 1917.
Awarded bar to DSO for distinguished service in the field, 1 January 1918.
Relinquishes command of 2nd New Zealand Infantry Brigade and resumes command of 2nd Battalion, Canterbury Infantry Regiment, 10 January 1918.
12 Alexandrina Kathleen Johnston, Uttoxeter, Staffordshire, England, 21 February 1918.
Appointed to command 2nd New Zealand Infantry Brigade, 6 August 1918; relinquishes command of 2nd New Zealand Infantry Brigade, and resumes command of 2nd Battalion, Canterbury Infantry Regiment, 22 August 1918.
Embarked onboard HMNZT 'Ruahine' in England and commenced return to New Zealand, 3 November 1919; disembarked at Wellington, 26 December 1919. Struck off strength of New Zealand Expeditionary Force and absorbed into the Reserve of Officers with rank of lieutenant-colonel, relinquishing temporary rank of colonel, 24 January 1920. AWMM