The regiment was first raised by Thomas Hickman-Windsor, 1st Earl of Plymouth as the Earl of Plymouth's Regiment of Horse in 1685 as part of the response to the Monmouth Rebellion, by the regimenting of various independent troops, and was ranked as the 4th Regiment of Horse. The regiment saw action at the Battle of Schellenberg in July 1704, the Battle of Blenheim in August 1704, the Battle of Ramillies in May 1706, the Battle of Oudenarde in July 1708 and the Battle of Malplaquet in September 1709 during the War of the Spanish Succession. In 1746 it was ranked as the 3rd Dragoon Guards, and formally titled in 1751 as the 3rd Regiment of Dragoon Guards.