The regiment took part in the Invasion of Île Bonaparte in July 1810 and, following the Invasion of Isle de France, occupied the island in March 1811 before returning to Madras in February 1812. Having become the 86th (Royal County Down) Regiment of Foot in May 1812, the regiment moved to Hyderabad in January 1816 from where it was involved in operations to suppress the Pindaris. It sailed for Trincomalee in Ceylon in September 1818 where it took part in operations to suppress the Kanyians and only embarked for home in April 1819.