 In May 1915, he transferred to the 18th Battalion, Middlesex Regiment, which was charged with clearing, repairing and building front-line trenches.In July 1916, the battalion was moved from its location near Béthune in order to assist in the attempted Capture of Fricourt.In 1917, Lawless was moved to the 26th Battalion, Middlesex Regiment, and was based in Salonika in November 1918.