Following the cessation of hostilities at the end of the French Revolutionary Wars, the 89th Regiment departed Egypt and joined an expedition sailing against Corfu. The expedition was countermanded and the Regiment returned to Ireland via Malta and Gibraltar, landing at the Cove of Cork on 28 January 1802.

The Regiment was stationed at Youghall, County Cork and then marched to Enniskillen, County Fermanagh. Lieutenant Colonel Lord Blayney assumed command around this time. During the Regiment’s next stations in Athlone and Loughrea, the Treaty of Amiens failed and the Napoleonic Wars began in May 1803. National preparations for war caused the 2nd Battalion of the 89th to be raised. The Regiment next occupied stations in County Cork at Doneraile and Cork City.

Following a countermanded order to sail to the West Indies on 13 July 1804, the 1/89th disembarked at Cork and marched to Kinsale where it remained until sailing in late November to join an expeditionary force bound for the Weser in 1805.