At Waterloo, the Scots Greys were part of the Union Brigade, a formation of heavy cavalry regiments held in reserve by Wellington and consisting of the 1st (Royal) Regiment of Dragoons, the 2nd (Royal North British) Dragoons, and the 6th (Inniskilling) Dragoons. In the line of battle, General Thomas Picton's 5th Division was held in reserve, on the left of the Allied line, behind the Dutch-Belgian 2nd Division. The 5th contained a number of experienced veteran units from the Peninsular War, including the 92nd Foot (Gordon Highlanders).