William entered the war in France on the 18th August 1914. His name was put forward to be awarded the Distinguished Conduct Medal by the officer commanding the 1st Field Ambulance to the Assistant Director of Medical Services, 1st Division on 16th August 1915. The citation read: "For conspicuous gallantry on many occasions under heavy fire, particularly on one occasion in attending to wounded." On 26th March 1916, the unit war diary states that 'Hanson' was evacuated yesterday 25th with a gun shot wound to arm left, caused by a bomb from German air craft.