[2] McBey was born in Newburgh, Aberdeenshire, Scotland, educated at his village school, and at the age of 15 years became a clerk in a local bank.

[3] At the start of World War I, McBey's poor eyesight prevented him enlisting as a soldier but in February 1916 he was commissioned as a temporary second lieutenant while employed with the Army Printing and Stationery Service,[6] based in Rouen.

While on leave there he completed two series of sketches, France at her Furnaces, showing the munition works at Harfleur, and some views of the Somme.

[9] McBey spent five days on a reconnaissance mission in the Sinai Desert with an Imperial Camel Corps patrol, consisting of rough-riders from the Australian outback, and witnessed Allenby's entry into Jerusalem in December 1917.

Although the British government made little use of his work during the war, when he returned to Britain McBey produced a series of etchings based on his drawings of the Camel Corps patrol.

[11] McBey also had commissions to paint a number of formal portraits, including one of Sir Harry Lauder in 1921, which today is in the Glasgow Museums.