Lieutenant-Colonel Alexander Daniel Reid was killed on the first day of the Battle of Passchendaele in 1917. His body was never recovered; however, there is nothing singular about that. What is remarkable is that his eloquent journal has survived untouched for 100 years. The context for Alexander Daniel Reid’s contemporary account of the Great War are provided partly by the memoirs of his brother, Harry, who was the transport officer in the same battalion, and partly from historical research. Although it is essentially a biography of two Scottish-born brothers in an Irish battalion on the Western Front, Harvest of Battle: Brother Officers of the 7th Royal Inniskilling Fusiliers in the First World War is unique in that it reaches to the corners of the Empire and tells of conflicts from German South-West Africa to the Rand Rebellion of 1922. Alexander Daniel Reid was a professional soldier and served with the Indian Army before migrating to Canada. Harry began a career working for one of the wealthiest mining magnates in Johannesburg. Both knew that their chances of survival in the ‘Fighting Seventh’ Royal Inniskilling Fusiliers were slim. Theirs is a narrative common enough to serve as a general introduction to the First World War for a new generation of readers, yet it contains valuable new material to add to the historical record in this Centenary year of the outbreak of war.