Question: What country do this social and ethnic group, to which William Stewart, 1st Viscount Mountjoy belongs and that are mostly the descendants and successors of the English Protestant Ascendancy, live?

Context paragraphs:
Edward Butler, 2nd Viscount Galmoye: Edward Butler, 2nd Viscount Galmoye (c. 1627– after 24 October 1667) was the son of Piers Butler of Duiske and Margaret Netterville, daughter of Nicholas Netterville, 1st Viscount Netterville.  His grandfather was Edward Butler, 1st Viscount Galmoye.

Anglo-Irish people: Anglo-Irish (Irish: "Angla-Éireannach" ) is a term which was more commonly used in the 19th and early 20th centuries to identify a social class and ethnic group in Ireland, whose members are mostly the descendants and successors of the English Protestant Ascendancy.  They mostly belong to the Anglican Church of Ireland, which was the established church of Ireland until 1871, or to a lesser extent one of the English dissenting churches, such as the Methodist church, though some were also Catholic.  Its members tended to follow English practices in matters of culture, science, law, agriculture and politics but often defined themselves as simply "Irish" or "British", rather than "Anglo-Irish" or "English".  Many became eminent as administrators in the British Empire and as senior army and naval officers.

Mountjoy Square: Mountjoy Square (Irish: "Cearnóg Mhuinseo" ) is a Georgian garden square in Dublin, Ireland, on the north side of the city just under a kilometre from the River Liffey.  One of five Georgian squares in Dublin, it was planned and developed in the late 18th century by the Luke Gardiner, 1st Viscount Mountjoy.  It was surrounded on all sides by terraced, red-brick Georgian houses.  Construction began in the early 1790s and the work was completed in 1818.

William Stewart, 2nd Viscount Mountjoy: William Stewart, 2nd Viscount Mountjoy (1675 - 10 January 1728), was an Anglo-Irish peer.

William Stewart, 1st Earl of Blessington: William Stewart, 1st Earl of Blessington (7 April 170914 August 1769) was an Anglo-Irish peer and member of the House of Lords, styled The Honourable William Stewart until 1728 and known as The Viscount Mountjoy from 1728 to 1745.

Luke Gardiner, 1st Viscount Mountjoy: Luke Gardiner, 1st Viscount Mountjoy PC (Ire) (7 February 1745 – 5 June 1798) was an Irish landowner and politician.

Baron Bayning: Baron Bayning, of Foxley in the County of Berkshire, was a title in the Peerage of Great Britain.  It was created in 1797 for the politician Charles Townshend.  He was the son of William Townshend, third son of Charles Townshend, 2nd Viscount Townshend (from whom the Marquesses Townshend descend) and the cousin of Thomas Townshend, 1st Viscount Sydney.  Townshend descended through his mother from Anne Murray, Viscountess Bayning, and Paul Bayning, 1st Viscount Bayning, hence his choice of title.  He was succeeded by his eldest son, the second Baron.  He represented Truro in Parliament.  In 1821 he assumed by Royal licence the surname of Powlett in lieu of Townshend.  He died unmarried and was succeeded by his younger brother, the third Baron.  He died without surviving male issue and the barony became extinct on his death in 1866.

William Stewart, 1st Viscount Mountjoy: William Stewart, 1st Viscount Mountjoy (1650 or 16533 August 1692), was an Anglo-Irish peer and soldier.

Statue of the Viscount Montgomery, London: The statue of Bernard Montgomery, 1st Viscount Montgomery of Alamein is located outside the Ministry of Defence Main Building in Whitehall, London, United Kingdom.  It was designed by Oscar Nemon and stands alongside statues of William Slim, 1st Viscount Slim and Alan Brooke, 1st Viscount Alanbrooke.

Charles Gardiner, 1st Earl of Blessington: Charles John Gardiner, 1st Earl of Blessington (1782 – 25 May 1829) was an Irish earl best known for his marriage to Margaret Farmer, née Power, whom he married at St Mary's, Bryanston Square, London, on 16 February 1818 (only four months after her first husband's death).  He was elected a representative peer in 1809, created Earl of Blessington in 1816, and inherited the title of Viscount Mountjoy in 1829.  He was present at the trial of Queen Caroline.

Supporting paragraphs: William Stewart, 1st Viscount Mountjoy Anglo-Irish people
Answer: Ireland