The Welsh Horse Yeomanry was a yeomanry regiment of the British Army that served in the First World War. The regiment was raised shortly after the outbreak of the war. Initially it served in East Anglia on anti-invasion duties, before being dismounted in 1915 and sent to take part in the Gallipoli Campaign. After withdrawal to Egypt, it was amalgamated with the 1/1st Montgomeryshire Yeomanry as the 25th (Montgomery and Welsh Horse Yeomanry) Battalion, Royal Welch Fusiliers and served as such throughout the rest of the war. It took part in the Sinai and Palestine Campaign in 1917 and 1918, before being transferred to the Western Front where it remained until the end of the war. The regiment formed 2nd and 3rd Lines in 1914, but these never left the United Kingdom before being disbanded in 1916 and early 1917, respectively. The 1st Line was disbanded in 1919. History Formation and early history The Welsh Horse Yeomanry was raised on 18 August 1914 in South Wales by the Glamorganshire Territorial Force Association, with HQ at Sophia Gardens in Cardiff (since demolished). Later in the year, it was transferred to Montgomeryshire County T.F. Association, with HQ now at Newtown. The regiment was trained and equipped as lancers. Despite being the last yeomanry regiment to be raised, it was accorded precedence after the Glamorganshire Yeomanry due to its connection to the Glamorganshire T.F. Association at the time of its formation. In accordance with the Territorial and Reserve Forces Act 1907 (7 Edw. 7, c.9) which brought the Territorial Force into being, the TF was intended to be a home defence force for service during wartime and members could not be compelled to serve outside the country. However, on the outbreak of war on 4 August 1914, many members volunteered for Imperial Service. Therefore, TF units were split in August and September 1914 into 1st Line (liable for overseas service) and 2nd Line (home service for those unable or unwilling to serve overseas) units. Later, a 3rd Line was formed to act as a reserve, providing trained replacements for the 1st and 2nd Line regiments. 1/1st Welsh Horse Yeomanry From early 1915, the 1st Line regiment was in 1/1st North Midland Mounted Brigade of 1st Mounted Division in the Diss area, replacing the Leicestershire Yeomanry which had been posted to 7th Cavalry Brigade with the British Expeditionary Force on the Western Front. About