Charles Mackesy, a married man with several children, volunteered for service on the outbreak of war and left New Zealand with the rank of Lieut. Colonel, as officer commanding the Auckland Mounted Rifles. After a brief period on Gallipoli he returned to Egypt to take charge of the New Zealand Mounted Rifle Brigade Base. On several occasions during the 1916-1918 Sinai-Palestine campaigns he commanded the Mounted Rifles. His services were honoured with the award of a Distinguished Service Order (DSO) and his appointment as Companion of the Order of St Michael and St George (CMG) in 1917. During late 1918 he served briefly as military governor of Salt and Amman, and stayed on for several months as advisor to the new Arab administration. In 1919 he was appointed Commander of the Order of the British Empire (CBE).

Charles Mackesy returned to New Zealand in 1919 and resumed farming near Whangarei. He died of heart failure in 1925. His collection was shortly afterwards presented to the Museum by Mrs Mackesy.

Three of his sons also served overseas during the war, and one, Harry Mackesy, was killed during the assault on Chunuk Bair in August 1915.

see: http://www.teara.govt.nz/en/biographies/3m19/mackesy-charles-ernest-randolph5.