 Nyorai mberi kweiyi ndima - Brereton akaberekwa muna 1789, uye akapinda muRoyal Military Academy se Gentleman Cadet muna 1803, achibuda musi wa10 Chivabvu 1805 semutevedzeri wechipiri muRoyal Artillery, uye achiwana kukwidziridzwa kuita lieutenant wekutanga musi wa7 Chikumi 1806. Akashanda muPeninsular neWaterloo mishandirapamwe kubva muna Zvita 1809 kusvika Chikumi 1815, kusanganisira dziviriro yeCádiz, kwaakatungamira zvombo paFort Matagorda, hondo yeBarrosa, kwaakakuvadzwa, Burgos kudzokera shure, hondo dzeVitoria nePyrenees, kukombwa kweSan Sebastián, kwaakange akabatanidzwa kwenguva pfupi kumabhatiri ekuputsa, hondo dzeOrthez, Toulouse, Quatre Bras, uye Waterloo. Munguva yakawanda yenguva yacho, aive mumwe wevashandi ve H Troop yeRoyal Horse Artillery yaitungamirirwa naMajor W. Norman Ramsay, iyo yaakakuvadzwa zvakaipisisa paWaterloo. Akava kaputeni wechipiri musi wa 5 Mbudzi 1816, uye akaiswa muhafu-mubhadharo gore rakatevera. Musi wa 23 Ndira 1819, achiri mubhadharo wehafu, akasimudzirwa kuva mukuru. Akaunzwa pamubhadharo uzere zvakare muna 1823, uye, akaita basa rakasiyana-siyana kumba uye mumakoroni. Akapfekedzwa seKnight weRoyal Guelphic Order muna 1837 uye seShamwari yeOrder yeBhati muna 1838. Brereton akashanda saInspector-General weIrish Constabulary pakati pa1839 na1843, achisimudzirwa kuva lieutenant-colonel musi wa17 Nyamavhuvhu 1843. 