The Scottish Rifles Brigade was originally a Volunteer Infantry Brigade formed in 1902 when the former Glasgow Brigade of the Volunteer Force was split up. The four Volunteer Battalions of the Cameronians constituted one brigade, while the four Volunteer Battalions of the Highland Light Infantry formed the other. From 1902 to 1908 the Scottish Rifles Brigade had the following composition:
After the Volunteers were subsumed into the new Territorial Force under the Haldane Reforms of 1908, the Scottish Rifles Brigade formed part of the Lowland Division of the TF with the following composition:
5th Battalion, Cameronians, at Glasgow
6th Battalion, Cameronians, at Muirhall, Hamilton
7th Battalion, Cameronians, at Victoria Road, Glasgow
8th Battalion, Cameronians, at Cathedral Street, Glasgow
First World War
The Lowland Division was mobilised for full-time war service in early August 1914, and most of the men, when asked, volunteered for overseas service. From November 1914 to March 1915, many units of the division were posted elsewhere, mainly to reinforce the Regular Army divisions of the British Expeditionary Forceon the Western Front, most of which had suffered heavy casualties. The 5th and 6th battalions of the Cameronians were sent to the Western Front and replaced by the 4th and 7th battalions of the Royal Scots. In May 1915 the division was numbered as the 52nd Division and the brigades were also numbered, the Scottish Rifles Brigade becoming 156th Brigade and the battalions were redesignated, becoming '1/7th Royal Scots', to distinguish them from their 2nd Line units being formed in the 195th Brigade, part of the 65th Division. During the war the brigade served with the division in the Middle Eastern theatre, fighting in 1917 in the Battle of Romani, the First Battle of Gaza, Second Battle of Gaza and Third Battle of Gaza during the Sinai and Palestine Campaign and, in 1918, served on the Western Front, fighting in the Hundred Days Offensive.
After the war the brigade and division were disbanded as was the whole of the Territorial Force. The Territorial Force was reformed in the 1920s as the Territorial Army and the 52nd Division was reconstituted as was the brigade which was redesignated as the 156th Infantry Brigade with the same unit it had pre-war. In 1921, the 5th and 8th Battalions of the Cameronians were amalgamated as the 5th/8th Battalion and were replaced by the 4th/5th Battalion, Royal Scots Fusiliers from the 155th Infantry Brigade. Shortly after, the brigade was redesignated the 156th Infantry Brigade. In the late 1930s many of the Territorial Army's infantry battalions were converted into other roles, mainly anti-aircraft and searchlight units. In late 1938, all British infantry brigades were reduced from four to three battalions and the 5th/8th Cameronians was chosen to be converted and became 5th/8th Battalion, Cameronians . In 1939 the brigade was redesignated 156th Infantry Brigade.