'During the attack on the Messines Ridge on 7th June 917 all the Officers (except one) of Sergeant Jackson's Company became casualties. Sergeant Jackson, as the senior non-commissioned officer, immediately took charge of a Platoon, and led it in the attack, leading to the destruction of the Garrison of Birthday Farm, which was very strongly held by machine-gun. Thenceforward Sergeant Jackson supervised the work of two platoons during consolidation, and was indefatigable, during heavy hostile shelling, in encouraging the men, setting them a fine example of coolness and bravery. During 7th, 8th, and 9th June he carried on, although practically tired out, assisting the one remaining Officer, and it is to the fine work of consolidation done under the partial supervision of Sergeant Jackson that the Company owes its comparatively small loss under heavy shelling.'
Source: 'London Gazette'
Date: 21 August 1917