 Complete the following phrase:  Britain had increased its cavalry reserves after seeing the effectiveness of mounted Boers during the Second Boer War 18991902. Horse-mounted units were used from the earliest days of World War I: on August 22, 1914, the first British shot of the war in France was fired by a cavalryman, Edward Thomas of the 4th Royal Irish Dragoon Guards, near Casteau, during a patrol in the buildup to the 