Black was born in Beremboke, near Bacchus Marsh, Victoria, the eleventh child of William and Anne (née Longmore), farmers originally from Antrim, Ireland.

Black and Murray, who would become the most decorated Australian soldier in the war, trained together on the Maxim Gun and became firm friends.

[3] While in London, Black was awarded the Distinguished Service Order (DSO) and the French Croix de guerre for his actions at Pozières and Mouquet Farm.

[1][3][10][11] The citation for his DSO was published in a supplement to the London Gazette on 14 November 1916 and read: Maj. Percy Black, Inf.

He led his company over "No Man's Land" against an enemy's [sic] strong point, which he captured and consolidated under very difficult circumstances, and under heavy artillery and machine gun fire.

Dodging the busy traffic around Piccadilly Circus, Black drolly remarked to his companion, "I’ll be glad to get back to the battalion, mate.

His battalion was exposed to uncut wire and machine gun fire after a tank offensive failed to clear a passage.

A group led by Lambis Englezos—who began the work that led to the recovery of over 200 men missing after the Battle of Fromelles, and reinterred at the new Fromelles (Pheasant Wood) Military Cemetery earlier in 2010—found eyewitness reports from Allied prisoners of war who were ordered by the Germans to bury the men in shell holes after the Battle of Bullecourt.

[13] While Black was renowned for his courage, Murray claimed that "Percy never went berserk and never sought death" and "had all the fear of the unknown".