 The 2nd Line regiment was formed in 1914.In 1915 it was under the command of the 2/1st Lowland Mounted Brigade in Scotland (along with the 2/1st Ayrshire (Earl of Carrick's Own) Yeomanry and the 2/1st Lothians and Border Horse) and by March 1916 was at Dunbar, East Lothian.On 31 March 1916, the remaining Mounted Brigades were numbered in a single sequence and the brigade became 20th Mounted Brigade, still at Dunbar under Scottish Command.