 The brigade was originally formed in 1908 in the Territorial Force (TF) as the South Western Brigade attached to the Wessex Division.It was composed of four TF infantry battalions, the 4th and 5th of the Prince Albert's (Somerset Light Infantry), the 4th Battalion of the Dorsetshire Regiment, and the 4th Battalion of the Duke of Edinburgh's (Wiltshire Regiment).The division was mobilised in August 1914, shortly after the outbreak of the Great War.