John Hamilton, 1st Marquess of Hamilton
John Hamilton, 1st Marquess of Hamilton( – 26 April 1604) was a Scottish nobleman.
John Browne, 1st Marquess of Sligo
John Denis Browne, 1st Marquess of Sligo, KP, PC
(Ire) (11 June 1756 – 2 January 1809) was an Irish peer and politician, and was the son of Peter Browne, 2nd Earl of Altamont, and his wife Elizabeth, née Kelly, daughter of Denis Kelly, Chief Justice of Jamaica.
Browne was styled Viscount Westport from 1771 to 1780 and known as John Browne, 3rd Earl of Altamont from 1780 to 1800.
Browne represented Jamestown in the Irish House of Commons from 1776-1780, when he succeeded as Earl of Altamont.
He served as High Sheriff of Mayo for 1779.
He became Marquess of Sligo on 29 December 1800 and was appointed a Knight of the Order of St Patrick on 5 August 1800.
George Browne, 3rd Marquess of Sligo
George John Browne, 3rd Marquess of Sligo( 31 January 1820 – 30 August 1896) was an Irish peer.
The son of Howe Browne, 2nd Marquess of Sligo, George Browne was educated at Eton and Trinity College, Cambridge.
He married three times but died without male issue.
He married, Like his predecessors, Browne prided himself on being an enlightened landlord.
In the second year of the Great Irish Famine, Browne's tenants gathered at Westport House, the ancestral residence of the Marquesses of Sligo.
Browne assured his tenants of his support for them, and proceeded to hand them guns( without regard for his own safety), enabling them to hunt for game.
He also went into considerable debt in order to acquire cornmeal from the Americas, and converted most of Westport House into a soup kitchen for the starving peasants.
He is buried at Kensal Green Cemetery, London.
Terence Browne, 9th Marquess of Sligo
Terence Morris Browne, 9th Marquess of Sligo( Lord Terence Browne from 1903- 1951; 28 September 1873 – 28 July 1952) was an Irish peer.
Browne was a son of Henry Ulick Browne, 5th Marquess of Sligo and Catherine Henrietta Dickon.
He died unmarried and was succeeded by his nephew, the 10th Marquess.
John Browne, 4th Marquess of Sligo
John Thomas Browne, 4th Marquess of Sligo( 10 September 1824 – 30 December 1903), styled Lord John Browne until 1868, was an Irish politician and naval commander.
Browne served as a Liberal Member of Parliament for Mayo in Ireland from 1857 to 1868.
He had previously served as an officer of the Royal Navy.
In 1896, Browne became Marquess of Sligo on the death of his elder brother, the 3rd Marquess, also inheriting some of land and the family seat at Westport House, Westport, County Mayo.
He died unmarried and was succeeded by his brother, Henry.
Randal William MacDonnell, 1st Marquess of Antrim
Randal William MacDonnell, 1st Marquess of Antrim was an Irish peer.
Henry Browne, 5th Marquess of Sligo
Henry Ulick Browne, 5th Marquess of Sligo( 14 March 1831 – 24 February 1913), styled Lord Henry Browne until 1903, was an Irish peer.
Browne was the fourth son of Howe Browne, 2nd Marquess of Sligo, and Lady Hester Catherine de Burgh, daughter of John de Burgh, 13th Earl of Clanricarde.
He succeeded to the marquessate in December 1903, aged 72, on the death of his unmarried elder brother.
He married Catherine Henrietta Dicken, daughter of William Stephens Dicken, on 25 October 1855.
They had ten children:
He is buried to the north- east of the main chapel at Kensal Green Cemetery in London.
John Browne, 1st Earl of Altamont
John Browne, 1st Earl of Altamont( c.1709 – 4 July 1776), known as The Lord Mount Eagle between 1760 and 1768 and as The Viscount Westport between 1768 and 1771, was an Irish peer and politician.
Peter Browne, 2nd Earl of Altamont
Peter Browne, 2nd Earl of Altamont (c. 1731 - 28 December 1780) was an Irish landowner and MP.
He was the son of John Browne, 1st Earl of Altamont, and Anne Gore.
He married Elizabeth Kelly, the only child of Denis Kelly, on 16 April 1752.
Den(n)is Kelly was Chief Justice of Jamaica and the Brownes inherited the Jamaican sugar plantations as well as Lisduff estate and Spring Garden estate, both in the civil parish of Tynagh, Barony of Leitrim (County Galway).
The townland of Lisduff exceeds 264 acres while the townland of Spring Garden exceeds 275 acres.
The Lisduff estate was acquired from Denis Kelly's brother, Edmond Kelly.
The estate was enlarged by land purchases in the townland of Drumatober (also in the Barony of Leitrim, Abbeygormacan civil parish) and Garrancarf in 1749, and of the lands of Cormickoge from John Burke in 1750.
He adopted the additional surname of Kelly.
He was elected Member of Parliament for Mayo in the Parliament of Ireland for 1761 to 1768.
Denis Browne, 10th Marquess of Sligo
Denis Edward Browne, 10th Marquess of Sligo( 13 December 1908 – 11 September 1991), known as Denis Browne until 1952, was an Irish peer.
Browne was the son of Captain Lord Alfred Eden Browne, fifth son of Henry Browne, 5th Marquess of Sligo.
His mother was Cicely Wormald, daughter of Edward Wormald.
In 1952 he succeeded his uncle in the marquessate.
Lord Sligo married Jose Gauche, daughter of William Gauche, in 1930.
In 1982 his book" Westport House and the Brownes" was published.
He died in September 1991, aged 82, and was succeeded by his son, Jeremy Browne, 11th Marquess of Sligo.

Question: What is the date of death of John Browne, 1St Marquess Of Sligo's father?
Answer: 28 December 1780