Muttra. The regiment landed in France at the outbreak of the First World War as part of the 2nd Cavalry Brigade in the 1st Cavalry Division on 16 August 1914 for service on the Western Front. Perhaps the regiment's most notable engagement was on 22 August 1914, when one of its squadrons became the first members of the British Expeditionary Force to engage the German army in the First World War. Two full troops of British cavalry surprised four patrolling German cavalrymen of the 2nd Kuirassiers at Casteau near Mons. After a brief pursuit the British cavalry killed most of the German patrol. Captain Charles Hornby was reputed to have become the first British soldier to kill a German soldier, using his sword, and Drummer Edward Thomas is reputed to have fired the first British shots of the war. In 1921 the regiment was renamed the 4th Royal Irish Dragoon Guards. In 1922 it was amalgamated with 7th Dragoon Guards (Princess Royal's) to form the 4th/7th Dragoon Guards. Regimental museum The regimental collection is held in the York Army Museum at the Tower Street drill hall in York. Battle honours The regiment's battle honours were as follows: Early Wars: Peninsular, Balaklava, Sevastopol, Tel-el-Kebir, Egypt 1882 The Great War: Mons, Le Cateau, Retreat from Mons, Marne 1914, Aisne 1914, La Bassée 1914, Messines 1914, Armentières 1914, Ypres 1914 '15, St. Julien, Frezenberg, Bellewaarde, Somme 1916 '18, Flers-Courcelette, Arras 1917, Scarpe 1917, Cambrai 1917 '18, St. Quentin, Rosières, Amiens, Albert 1918, Hindenburg Line, Pursuit to Mons, France and Flanders 1914-18 Colonels The colonels of the regiment were as follows: Earl of Arran's Cuirassiers and 6th Regiment of Horse 1685-1688 Lieutenant-General James, Earl of Arran later Duke of Hamilton KG KT. app. 28 July 1685 —The Earl of Arran’s Horse 1688-1688 Colonel Charles, Earl of Selkirk. app. 20 November 1688 —The Earl of Selkirk’s Horse 1688-1693 Colonel Charles Godfrey. app. 31 December 1688 from 1691 5th Regiment of Horse 1693-1713 Lieutenant-General Francis Langston. app. 7 March 1693 — Langton’s Horse 1713-1715 Lieutenant-General George Jocelyn. app. 29 October 1713 —Jocelyn’s Horse 1715-1729 Major-General Sherrington Davenport. app. 9 February 1715 — Davenport’s Horse (also The Prince of Wales’s Own Regiment of Horse) 1729-1732 Lieutenant-General Owen Wynne. app. 6 July 1729 — Wynne’s Horse 1732-1739 Lieutenant-General Thomas Pearce. app. 29 September 1732 — Pearce’s Horse 1739-1743 Field Marshal James, Baron Kilmaine. app. 26 August 1739 —