The Territorial Force was established on 1 April 1908 as a volunteer auxiliary to the British Army. It was formed by the amalgamation of the former auxiliary institutions of the Volunteer Force and the yeomanry. Designed primarily as a home defence force, its members could not be compelled to serve overseas unless they volunteered to do so. On the outbreak of the First World War in 1914, many did. The first units were deployed piecemeal in support of the regular army as it defended against the opening German offensive in Belgium and France in 1914. The first territorial divisions to be deployed were used to free up imperial garrisons overseas, but in 1915 they began to be deployed to the front lines on the Western Front and at Gallipoli. The pre-war territorial divisions were numbered in May 1915 in order of their deployment. As they were deployed, second-line divisions were raised to replace them at home, and in 1916 these began to be deployed to combat zones. By the end of the war in 1918, the Territorial Force had provided 28 divisions and 14 mounted brigades.
Also by Major J Stirling and published by Naval & Military Press
OUR REGIMENTS IN SOUTH AFRICA 1899-1902. ISBN 9781843420279
THE COLONIALS IN SOUTH AFRICA 1899-1902: Their Record, Based On the Despatches. ISBN 9781843422778