- For events that took place elsewhere in the Great War, see The Great War:26 May.
Lonsdale Battalion events that took place on 26 May.
- Battalion situated at Crucifix Corner – relieves the 17th Highland Light Infantry in the Authuille Sector.
- Lieut. Gerald Spring-Rice, Transport Officer to the Battalion, is killed by a spent bullet. He was 52 years of age.
- “Before he joined he had done splendid work as Secretary of the Executive Committee, and from the time of his appointment as Transport Officer until the day of his death he devoted his entire energies to the welfare of the Battalion, in the formation of which he had such an important share.” – Lt-Col. P. W. Machell