Harry Moon and eight fellow members of the Royal Sussex Regiment all volunteered to transfer to B Battalion, Heavy Branch, Machine Gun Corps in January 1917, (later the Tank Corps) to serve in the revolutionary Mk IV Tanks. After describing hisexperiences, training and fighting on the Somme with the Royal Sussex, the book provides a unique description of the experiences of a tank crewman on the Western Front. The first action was at Messines in the Mk IV and Harry's story isembellished with accounts of gallantry by others and other anecdotes. After the battle he took part in two tank demonstrations for Royalty.The 3rd Battle of Ypres followed in July 1917 resulting in the death of one of Harry's fellow volunteers. A full and thrilling account of the mass use of armour at Cambrai follows after descriptions of trials of fascines and barbed wire clearingequipment. Here the Battalion successfully achieved their first, second and third objectives and celebrated with a white table cloth lunch on the Hindenburg Line! Tragically disaster was to follow at the attack on Fontaine-Notre-Dame on 23November where there were 70% casualties.Using personal accounts, Battle History reports and the Battalion War Diary, Tank Action in the Great War is a superb account of the early use of armour and the dangers for the crews. An additional feature is the array of exceptionally rare contemporary photographs of tank trials and combat casualties.