He was Member of Parliament (MP) for County Carlow for a total of about 36 years, in three separate periods between 1812 and 1852, taking his seat in the House of Commons of what was then the United Kingdom of Great Britain and Ireland.
[2] His father originally came from Boyle, County Roscommon, but had moved in 1775 to Oak Park estate, near Carlow town.
[7] However, the by-election was itself the subject of a petition, and the result was overturned, with Bruen being returned to Westminster, along with his father-in-law, fellow Conservative Thomas Kavanagh.
[7] He did not win a seat in 1837,[5] but returned to the House of Commons in 1840, when he won a by-election on 5 December after the death of the Liberal MP Nicholas Aylward Vigors.
[2] (Anne's younger half-brother was Arthur MacMorrough Kavanagh (1831–1889), the severely disabled writer, politician and sportsman).