This book attempts to document the history of the 5th (Royal Irish) Lancers from 1902 up until their disbandment and subsequent amalgamation with the 16th Lancers in 1922. Particular attention is paid to their service during the First World War where they served continuously on the Western Front from 1914 up until the Armistice in 1918. During this conflict they gained numerous battle honours and had the distinction of being the last British regiment to leave Mons during the great retreat in 1914. They were also the first British regiment to re-enter the town in 1918 on the day the war ended. They had previously served during the Boer War with distinction but their unswerving loyalty to the crown didn’t save them from disbandment in 1921 along with several other Irish regiments. Their traditions and name were preserved however, with the amalgamation of the 16th Lancers in 1922 to become the 16th / 5th Lancers, a fitting achievement for a regiment of the British Army who could trace their linage back to 1689. The book concentrates mainly on the Great War with information coming from war diaries, personal letters and officers and soldier’s military records. Also included is a rare account of the regiment’s service during the Irish rebellion of 1916 where, as part of the 6th Reserve Cavalry Regiment they fought against the Irish Republican rebels in Dublin. The last chapter concentrates on the service of a relation who served with regiment during the Great War and includes photos and images of documents. This book contains over 200 pages of text, images and maps (including trench maps) as well as a detailed appendix which includes a roll of honour, medal and award recipients (including numerous citations, officer lists and other information pertaining to the regiment. Also included are rare photographs, many from private collections which have never been published before.