Parsons, William, 3rd Earl of Rosse

• Lord Rosse

• Parsons, Lord, William, Baron of Oxmantown
• Parsons, Sir, William, 6th Baronet of Birr Castle
• Lord Oxmantown

William Parsons, 3rd Earl of Rosse, Baron of Oxmantown, 6th Baronet of Birr Castle, was born in June of 1800 to Lord Laurence Parsons, 2nd Earl of Rosse, and Lady Alice Lloyd. He served as a Member of Parliament from 1821-1834. Lord Rosse married Lady Mary Field, daughter of John Wilmer Field on 14 April 1836. Upon the death of his father, Laurence Parsons, 2nd Earl of Rosse in 1841, William became the 3rd Earl of Rosse. He was also President of the British Association from 1843-1844. Lord Rosse was president of the Royal Society from 1845-1854, while he also served as an Irish representative peer. From 1862-1867 he was chancellor of Trinity College, Dublin. Lord Rosse was an avid scientist, a passion that he shared with his wife, Mary Rosse, and is best known for building the 'Leviathan of Parsonstown,’ a 72-inch telescope. It was built in 1845 and was the largest telescope in the world. As an astronomer, he was first to discover the spiral nature of some nebulae (now called spiral galaxies), and naming the Crab Nebula. He died 31 October 1867, and was succeeded by his son, Laurence Parsons, 4th Earl of Rosse.

Sir Laurence Parsons (d.1698, created Baronet 1677) married Lady Frances, youngest daughter and co-heir of William Savage Esquire of Rheban, County Kildare, and was created Baronet of Birr Castle in 1677. He was succeeded in the baronetcy by his son, Sir William Parsons (d.1740), who married firstly Lady Elizabeth, daughter of Sir George Preston, Baronet of Craigmiller and they had one son. He married a second time to Lady Elizabeth, eldest daughter and co-heir of Sir George St. George, Knight. Sir William Parsons died in 1740 and his grandson, Sir Laurence Parsons (d.1749) succeeded him as 3rd Baronet of Birr Castle. In 1740 he first married Lady Mary, eldest daughter and co-heir of William Sprigge Esquire, and they had one son, Sir William Parsons (1721-1791). In 1742 he married again to Lady Anne, only daughter of Wentworth, Harman Esquire of Moyle, and niece and heir of the Very Reverend Dean Harman of Waterford. They had issue, Lord Laurence Parsons (1742-1807, created Baron of Oxmantown 1792, advanced to Viscount of Oxmantown 1795, created Earl of Rosse 1806). The 3rd Baronet of Birr Castle died in 1749, and his eldest son Sir William Parsons (1721-1791) succeeded him as 4th Baronet of Birr castle. He married in 1754 to Lady Mary, only daughter and heir of John Clere Esquire of Kilbury, descended from the Cleres of Ormsby in Norfolk. Sir William Parsons became head of the Parsons family after the death of Sir Richard Parsons, 2nd Earl of Rosse (c.1716-1764). William was succeeded in the baronetcy by his son, Laurence Parsons (1758-1841), who married Alice, daughter of John Lloyd Esquire of Gloster, King’s County. In 1807, he was elevated to the peerage as the second Earl of Rosse upon the death of his father’s half-brother. His son Sir William Parsons (1800-1867) succeeded him as the 6th Baronet and 3rd Earl of Rosse. In 1836 he married Lady Mary, eldest daughter and co-heir of John Wilmer Field Esquire of Heaton Hall, County York. He was succeeded in the earldom and baronetcy by their eldest son Laurence Parsons (1840-1908), who in 1905 married Lady Frances Lister-Kaye, daughter of Sir Cecil Lister-Kaye, fourth Baronet of Grange. Their son Laurence Michael Harvey Parsons (1906-1979) succeeded as the 6th Earl of Rosse in 1918. In 1935 he married Lady Anne Messel, daughter of Lieutenant-Colonel Leonard Charles Rudolph Messel. Their son Sir Brendan Parsons (b. 1936) married Lady Alison Margaret Cooke-Hurle, daughter of Major John Davey Cooke Hurle in 1966. He succeeded his father as the 7th Earl of Rosse in 1979. They have three children: Laurence Patrick Parsons, Lord Oxmantown (b.1969), Lady Alicia Parsons (b.1971), and the Honourable Michael Parsons (b.1981).

ISAAR (CPF): International Standard Archival Authority Record for Corporate Bodies, Persons and Families, 2nd edition (2011).

Jennifer Lee, May 2018.

Burke, John Bernard. A Genealogical and Heraldic Dictionary of the Peerage of the British Empire. London: Henry Colburn, 1851.
Mollan, Charles Editor. William Parsons, 3rd Earl of Rosse Astronomy and the Castle in Nineteenth-Century Ireland. Manchester: Manchester University Press, 2014.