He was descended from Sir William Brereton, Chief Justice and Lord High Marshal of Ireland, from the ancient and noble family of Brereton, Cheshire, England. Born in King's County (now County Offaly), Ireland, in 1782. 1798 he received his commission as an ensign in the 8th West India Regiment. 1809 he was promoted to Major and served at the capture of Martinique from the French and Guadelope the following year. He was appointed Brigade Major in 1813 for his relative Major General Robert Brereton, Lieutenant-Governor of St. Lucia. 1814 he was appointed Lieutenant-Governor of Senegal and Gorée and was present during the tragedy. 1815 he was promoted to Lieutenant-Colonel of the Royal African Corps. 1819 he was appointed to the command of the Cape Town garrison until 1823 when he retired to England to become Inspecting Field Officer for the Bristol recruiting district.