The Battle of the Selle is one of the forgotten battles of the Hundred Days campaign. It should, however, be regarded as one of the greatest military victories in the nation's history. A study of Fourth Army reveals how the balance of the contributions of all-arms would vary from battle to battle. The weather at the Selle denied the BEF intelligence from the air. Fourth Army did not know the enemy had been reinforced, and without great help from tanks and artillery that was less effective than on other occasions, the infantry fought a challenging battle in difficult countryside, reliant on the experience of commanders on the ground. Peter Hodgkinson is a Clinical Psychologist, with an MA (2006) in British First World War Studies at Birmingham University, and a PhD (2013) about British Infantry Battalion Commanders.