Dillon's Regiment was first raised in Ireland in 1688 by Theobald, 7th Viscount Dillon, for the Jacobite side in the Williamite War. He was then killed at the Battle of Aughrim in 1691. Dillon's Regiment was first raised as part of the Irish Army in 1688 by Theobald, 7th Viscount Dillon who was killed at the Battle of Aughrim. During the Williamite War the regiment went to France in April 1690 as part of Lord Mountcashel's Irish Brigade, in exchange for some French regiments amounting to 6,000 troops. In 1767 Arthur Dillon the great grandson of Theobald Dillon, 7th Viscount Dillon took command of the regiment. During the American Revolutionary War, the regiment participated in the Capture of Grenada, the Siege of Savannah, the Invasion of Tobago, and the Capture of Sint Eustatius. Detachments of the regiment were assigned to the French Fleet under Admiral François Joseph Paul de Grasse during the Battle of the Chesapeake. After the victory at Yorktown, the fleet sailed south and Dillon's Regiment participated in the Siege of Brimstone Hill.