Including Sir Robert Walpole, generally accepted as being (de facto) the first Prime Minister of Great Britain, 54 men and three women have held the office, nearly one quarter of them during the reign of the late Queen Elizabeth II. Links, mostly by marriage, to the Blackett family have been discovered to 42 of them, as shown below. Every Prime Minister of the 18th century and all but one (Benjamin Disraeli – see Note) of the 19th can be linked to the Blacketts. Even in the more democratic 20th century Prime Ministers with links to the Blacketts were in office in 52 years.
[Note. In 1852 Disraeli, then Chancellor of the Exchequer, made a lengthy and eloquent speech in the House of Commons on the death of the Duke of Wellington. Edward Algernon Blackett of Wylam discovered that a section of the speech was almost word for word a repetition of an encomium pronounced by M. Thiers on Marshal Gouvion de St. Cyr in 1829 which had been quoted in the Morning Chronicle in 1848. Blackett passed on his discovery to his brother, John Fenwick Burgoyne Blackett MP, who in turn informed The Globe, a newspaper founded by their grandfather in 1803. The Globe commented thus about Disraeli’s plagiarism: “We have seen him snatch a wreath of faded French artificial flowers for the pall of Wellington, with an audacity of larceny unsurpassed in Grub Street.” Paradoxically, however, the public seemed to enjoy the discovery of Disraeli’s plagiarism. As William S. Walsh put it in his “Handy-Book of Literary Curiosities” (1892): “…he gave his critics the pleasure of detecting him – a great delight accorded to a worthy and deserving and very hard-worked class. The whole of England was aroused, amused and interested.”]
Only two Prime Ministers, Arthur James Balfour and Sir Anthony Eden, (see 33 & 43 below) are direct descendants of Blacketts, but the descendants of a number of others also have Blackett ancestry. Some links to the Blacketts are via other Prime Ministers who were related to each other. In addition to the links shown there is a further link to 15 Prime Ministers who were descendants of Sir George Villiers, 3xgreat-grandfather of Lady Barbara Villiers, the second wife of Sir William Blackett. Those Prime Ministers are marked with a *.
(Some of the links are a little tortuous but are included for the sake of completeness and to illustrate the degree of inter-marriage between members of the ruling classes of the day).
PRIME MINISTERS, PERIOD OF OFFICE, POLITICAL PARTY AND LINKS TO BLACKETTS (clicking on the number will take you to their Wikipedia page)
18TH CENTURY
1. Sir Robert Walpole 1721-42 Whig – illegitimate granddaughter, Maria Walpole married to Prince William Henry Hanover, whose illegitimate daughter Louisa Maria la Coast married Sir Godfrey Bosville Macdonald, great-grandson of Diana Blackett. Sir Robert Walpole was also the 4xgreat-uncle of Reginald Horace Walpole, (great-grandson of Spencer Perceval – see 17 below), who married Agnes Edwardine Brewster Hancock, 4xgreat-granddaughter of Julia Blackett. A further link is through Reginald Horace Walpole's elder sister Margaret Walpole who married Walter Yarrowyck Wyndham, 4xgreat-grandson of Julia Blackett.
2. Spencer Compton, Earl of Wilmington 1742-3 Whig – 5xgreat-great-uncle of Edward Robert Francis Compton, 6xgreat-grandson of Elizabeth Blackett.
3. Henry Pelham 1743-54 Whig – brother-in-law of Lady Henrietta Godolphin, great-great-aunt of George Godolphin Osborne, 8th Duke of Leeds, who was a 3xgreat-grandson of Elizabeth Blackett. He was also the brother of Thomas Pelham-Holles (see 4 below), and was married to Lady Catherine Manners, 1st cousin 3xremoved of John Russell, Earl Russell (see 25 below)
4. Thomas Pelham-Holles, Duke of Newcastle 1754-6 and 1757-62 Whig – brother of Henry Pelham (see 3 above).
5. * William Cavendish, Duke of Devonshire 1756-1757 Whig – father-in-law of Lady Georgiana Spencer, the aunt of Harriet Emma Arundel Stewart, who married George Godolphin Osborne, 8th Duke of Leeds, 3xgreat-grandson of Elizabeth Blackett. Harriet was also the half-sister of Lady Caroline Ponsonby, who married William Lamb, 2nd Viscount Melbourne (see 18 & 23 below) Please also see Cavendish Connections.
6. John Stuart, Earl of Bute 1762-3 Tory – great-grandfather of John George Blackett Dawson, grandson of Anne Blackett.
7. George Grenville 1763-5 Whig – husband of Elizabeth Wyndham, who was a 2nd cousin 3xremoved of George Godolphin Osborne, Marquess of Carmarthen and 9th Duke of Leeds, 4xgreat-grandson of Elizabeth Blackett, and a 6xgreat-great-aunt of David Cameron (see 53 below). George Grenville was also father of William Wyndham Grenville, 1st Baron Grenville (see 16 below), was the brother-in-law of The Earl of Chatham, William Pitt ‘The Elder’ (see 9 below), an uncle of William Pitt ‘The Younger’ (see 14 below), and was a 2xgreat-great-uncle of Archibald Primrose, 5th Earl of Rosebery (see 32 below).
8. Charles Watson-Wentworth, Marquess of Rockingham 1765-6 and 1782 Whig – brother of Lady Ann Watson-Wentworth, great-great-grandmother of William Hugh Spencer Wentworth Fitzwilliam, who married Lady Ada Charlotte Godolphin Osborne, 5xgreat-granddaughter of Elizabeth Blackett. William Hugh Spencer Wentworth Fitzwilliam was also the 1st cousin twice removed of Lady Caroline Ponsonby, who married William Lamb, 2nd Viscount Melbourne (see 23 below).
9. * The Earl of Chatham, William Pitt ‘The Elder’ 1766-8 Whig – brother-in-law of George Grenville (see 7 above), uncle by marriage of William Wyndham Grenville, 1st Baron Grenville (see 16 below) and father of William Pitt ‘The Younger’ (see 14 below).
10. * Augustus Henry Fitzroy, Duke of Grafton 1768-70 Whig – 3xgreat-grandfather of Francis Edward Scudamore St. Clair-Erskine, Lord Loughborough, 6xgreat-grandson of Elizabeth Blackett.
11. Lord North 1770-82 Tory – great-great-uncle of Dudley Francis North, 7th Earl of Guildford, 4xgreat-grandson of Elizabeth Blackett.
12. William Petty, Earl of Shelburne 1782-3 Whig – great-grandfather of Lady Mary Caroline Louisa Thomas Petty-FitzMaurice, first cousin 1xremoved of George Godolphin Osborne, Marquess of Carmarthen and 9th Duke of Leeds, 4xgreat-grandson of Elizabeth Blackett. Lady Mary Caroline Louisa Thomas Petty-FitzMaurice was also the mother-in -law of Thomas Richard Cholmondeley, great-great-grandson of Sir Thomas Wentworth Blackett. William Petty’s 4xgreat-nephew, Sir Christopher Bullock was the husband of Barbara May Lupton, a 2nd cousin 3xremoved of Catherine Elizabeth Middleton, who in 2011 married Prince William Arthur Philip Louis Windsor, now Prince of Wales and heir to the throne. There is believed to be a further distant link through the Fairfax family, but this has not been examined.
13. * William Cavendish-Bentinck, Duke of Portland 1783 and 1807-9 Whig – 4xgreat-grandfather of Lady Diana Evelyn Bowes-Lyon, wife of Christopher Godfrey-Faussett, 7xgreat-grandson of Julia Blackett. He was also the father-in-law of Lady Anne Wellesley, niece of Arthur Wellesley, 1st Duke of Wellington (see 21 below) and was married to Dorothy Cavendish, 3xgreat-great-aunt of Lady Dorothy Evelyn Cavendish, the wife of Maurice Harold Macmillan (see 44 below).
19TH CENTURY
14. * William Pitt ‘The Younger’ 1783-1801 and 1804-6 Tory – (i) son of The Earl of Chatham, William Pitt ‘The Elder’ (see 9 above), (ii) nephew of George Grenville (see 7 above), (iii) 1st cousin of William Wyndham Grenville (see 16 below) (iv) 1st cousin 3xremoved of The Earl of Rosebery (see 32 below).
15. Henry Addington 1801-1804 Tory. Great-grandfather of Mabel Addington who married Sir Archibald Ernest Orr Ewing, brother-in-law of Lady Margaret Frances Susan Innes-Ker, 1st cousin of Sir Winston Leonard Spencer Churchill, (see 41 below).
16. * William Wyndam Grenville, Lord Grenville 1806-7 Whig – (i) son of George Grenville (see 7 above), (ii) husband of Anne Pitt, great-niece of The Earl of Chatham, William Pitt ‘The Elder’ (see 9 above) (iii) 1st cousin 1xremoved of William Pitt ‘The Younger’ (see 14 above). He was also a 1st cousin 7xremoved of David Cameron (see 53 below.)
17. Spencer Perceval 1809-12 Tory – (i) brother-in-law of Maria Wilson, the wife of Sir John Trevelyan, great-grandson of Julia Blackett (ii) father of Ernest Augustus Perceval, who married Beatrice Trevelyan, great-great-granddaughter of Julia Blackett (iii) uncle of Charles George Perceval, who married Frances Agnes Trevelyan another great-great-granddaughter of Julia Blackett (iv) great-grandfather of Reginald Horace Walpole, who married Agnes Edwardine Brewster Hancock, 4xgreat-granddaughter of Julia Blackett (v) great-grandfather of Margaret Walpole who married Walter Yarrowyck Wyndham, 4xgreat-grandson of Julia Blackett. (Sir Robert Walpole, see 1 above, was 4xgreat-uncle of Reginald Horace Walpole and Margaret Walpole.
18. Robert Banks Jenkinson, Earl of Liverpool 1812-27 Tory – half-brother of Charles Cecil Cope Jenkinson, the father-in-law of Francis Venables-Vernon-Harcourt, who was 1st cousin of Harriet Emma Arundel Stewart, the wife of George Godolphin Osborne, 8th Duke of Leeds, 3xgreat-grandson of Elizabeth Blackett. (see also 5 above and 23 and 28 below).
19. George Canning 1827 Tory – great-grandfather of Wentworth Canning Blackett Beaumont, 2xgreat-grandson of Sir Thomas Wentworth Blackett.
20. Frederick Robinson, Viscount Goderich 1827-8 Tory – 6th cousin once removed of Charles William Campbell, 9th Earl of Breadalbane and Holland, 6xgreat-grandson of Elizabeth Blackett.
21. Arthur Wellesley, Duke of Wellington 1828-30 and 1834 Tory – 4xgreat-great uncle of Lady Diana Evelyn Bowes-Lyon, who married Christopher Godfrey-Faussett, 7xgreat-grandson of Julia Blackett. (see also 13 above).
22. Earl Grey 1830-34 Whig – (i) great-great-grandfather of Charles William Lambton, 6xgreat-grandson of Diana Blackett, (ii) great-grandfather of Henry Frederick Compton Cavendish, who married Lady Harriet Castalia Godolphin Osborne, 5xgreat-granddaughter of Elizabeth Blackett, (iii) great-grandfather of Lady Katherine Frances Lambton, who married George Godolphin Osborne, 10th Duke of Leeds, 5xgreat-grandson of Elizabeth Blackett (see also 25, 26, 27 and 45 below) (iv) great-great-uncle of Sir Anthony Eden (see 43 below) (v) great-uncle of Laura Jane Grey who married Edward Ralph Blacket.
23. * William Lamb, Viscount Melbourne 1834 and 1835-41 Whig – brother-in-law of Harriet Emma Arundel Stewart, who married George Godolphin Osborne, 8th Duke of Leeds, 3xgreat-grandson of Elizabeth Blackett. He was also brother-in-law of Viscount Palmerston (see 28 below). (See also 5, 8 and 18 above and 53 below).
24. Sir Robert Peel 1834-5 and 1841-6 Tory – brother-in-law of Robert Henry Eden Henley, 2nd Baron of Chardstock, great-great-grandson of Elizabeth Blackett (see also 40 and 53 below).
25. * Earl Russell 1846-51 1865-6 Liberal – (i) great-great-uncle of Lady Gwendolen Fanny Godolphin Osborne, 6xgreat-granddaughter of Elizabeth Blackett, (ii) great-great-uncle of Charles William Lambton, 6xgreat-grandson of Diana Blackett. (see also 3, 18 and 22 above, 26, 27, 44 and 45 below).
26. * The Earl of Derby 1852, 1858-9 and 1866-8, Conservative – (i) 9th cousin 3xremoved of Charles William Lambton, 6xgreat-grandson of Diana Blackett (ii) 9th cousin 3xremoved of Lady Gwendolen Fanny Godolphin Osborne, 6xgreat-granddaughter of Elizabeth Blackett. (see also 22 and 25 above and 27 below).
27. * Earl of Aberdeen 1852-1855 Tory – husband of Lady Catherine Elizabeth Hamilton who was (i) great-great aunt of Charles Lambton, who married Lavinia Marion Garforth, 5xgreat-granddaughter of Diana Blackett (ii) great-great-aunt of Lady Katherine Frances Lambton, who married George Godolphin Osborne, 10th Duke of Leeds, 5xgreat-great-grandson of Elizabeth Blackett. (see also 22, 25 and 26 above).
28. Viscount Palmerston 1855-8 and 1859-65 Liberal – brother-in-law of William Lamb, Viscount Melbourne (see 23 above).
29. Benjamin Disraeli 1868 and 1874-80 Conservative – no link found.
30. William Ewart Gladstone 1868-74, 1880-85, 1886 and 1892-94 Liberal – great-great-uncle of Robert John Patrick Eden, 5xgreat-grandson of Elizabeth Blackett.
31. * Robert Gascoyne-Cecil, Marquess of Salisbury 1885-6, 1886-92 and 1895-1902 Conservative – (i) uncle of Algernon Cecil, who married Lady Gwendolen Fanny Godolphin Osborne, 6xgreat-granddaughter of Elizabeth Blackett, (ii) uncle of Arthur James Balfour (see 33 below).
32. The Earl of Rosebery 1894-5 Liberal – (i) 1st cousin 3xremoved of William Pitt ‘The Younger’ (see 14 above) (ii) 2xgreat-great-nephew of George Grenville (see 7 above).
20TH CENTURY
33. * Arthur James Balfour 1902-5 Conservative – (i) 5xgreat-grandson of Bridgett Blackett (ii) 1st cousin of Algernon Cecil, husband of Lady Gwendolen Fanny Godolphin Osborne, 6xgreat-granddaughter of Elizabeth Blackett, (iii) nephew of Robert Gascoyne-Cecil, Marquess of Salisbury (see 31 above).
34. Henry Campbell-Bannerman 1905-8 Liberal – possibly related to Marjorie Sadie J. Campbell-Bannerman, who married in 1938 Christopher Hugh Fagan, 4xgreat-grandson of Ann Blackett. The link has however not yet been established.
35. Herbert Henry Asquith 1908-16 Liberal – great-great-nephew of Robert Wrigley, who married Ann Blackett.
36. David Lloyd George 1916-22 Liberal – no link found.
37. Andrew Bonar Law 1922-3 Conservative – grandfather of Bonar Hugh Charles Sykes, brother-in-law of Veronica Nell Fraser, great-great-niece of Adelaide Lister, who married Maurice Drummond, 3xgreat-grandson of Elizabeth Blackett.
38. Stanley Baldwin 1923, 1924-9, 1935-7 Conservative – husband of Lucy ‘Cissie’ Ridsdale, 4xgreat-niece of Edward Ridsdale, who eloped with Anne Blackett, daughter of Sir Edward Blackett 2nd Bt., in 1709.
39. James Ramsay MacDonald 1924 and 1929-35 Labour and National Government– no link found
40. Arthur Neville Chamberlain 1937-40 Conservative – uncle by marriage of John William Burke Cole, husband of Mary Bridget Anne Crichton, who was the 3xgreat-granddaughter of Sir Robert Peel (see 24 above) and 3xgreat-great-niece of Harriet Eleonora Peel, wife of Robert Henry Eden Henley, 2nd Baron of Chardstock, great-great-grandson of Elizabeth Blackett.
41. * Sir Winston Leonard Spencer Churchill 1940-5 and 1951-5 Conservative – (i) 4th cousin 2xremoved of George Godolphin Osborne, Marquess of Carmarthen and 9th Duke of Leeds, who was a 4xgreat-grandson of Elizabeth Blackett (ii) 1st cousin of Lady Margaret Frances Susan Innes-Ker, sister-in-law of Sir Archibald Ernest Orr Ewing, who married Mabel Addington, great-granddaughter of Henry Addington (see 15 above) (iii) 6th cousin of Lady Dorothy Evelyn Cavendish, wife of Harold Macmillan, 1st Earl of Stockton (see 44 below) (iv) 6th cousin 1xremoved of Sir Alec Douglas-Home (see 45 below).
42. Clement Richard Attlee 1945-51 Labour – no link found.
43. * Anthony Eden 1955-7 Conservative – 5xgreat-grandson of Elizabeth Blackett. He was also the great-great-nephew of Earl Grey (see 22 above).
44. Harold Macmillan, 1st Earl of Stockton 1957-63 Conservative – husband of Lady Dorothy Evelyn Cavendish who was (i) 4th cousin 1xremoved of George Godolphin Osborne, 10th Duke of Leeds, 5xgreat-grandson of Elizabeth Blackett (ii) great-great-niece of John Russell, 1st Earl Russell (see 25 above) (iii) 3xgreat-great-niece of Dorothy Cavendish, wife of William Henry Cavendish-Bentinck, 3rd Duke of Portland (see 13 above) (iv) 6th cousin of Sir Winston Leonard Spencer Churchill (see 41 above) (v) 2nd cousin 1xremoved of Sir Alec Douglas-Home (see 45 below).
45. * Sir Alec Douglas-Home 1963-4 Conservative – (i) 3xgreat-great-grandson of Charles Grey, 2nd Earl Grey (see 22 above), (ii) 2xgreat-great-nephew of John Russell, 1st Earl Russell (see 25 above), (iii) 6th cousin 1xremoved of Sir Winston Leonard Spencer Churchill (see 41 above) (iv) 2nd cousin 1xremoved of Lady Dorothy Evelyn Cavendish (see 44 above) (v) brother-in-law of Joan Argentine Alington, wife of Rev. John Comyn Vaughan Wilkes, great-grandson of Ellen Anne Blacket (vi) brother-in-law of Rachel Leila Brand, 7xgreat-granddaughter of Diana Blackett.
46. Harold Wilson 1964-70 and 1974-6 Labour – no link found.
47. Edward Heath 1970-4 Conservative – no link found.
48. James Callaghan 1976-9 Labour – no link found.
49. Margaret Thatcher 1979-90 Conservative – no link found.
50. John Major 1990-97 Conservative – no link found.
51. Tony Blair 1997-2007 Labour. 11th cousin 1xremoved of Patrick Bowes-Lyon, 15th Earl of Strathmore, who married Lady Dorothy Beatrix Godolphin Osborne, 6xgreat-granddaughter of Elizabeth Blackett.
21ST CENTURY
52. Gordon Brown 2007-2010 Labour – no link found.
53. David Cameron 2010-2016 Conservative – (i) 6xgreat-great-nephew of Elizabeth Wyndham, wife of George Grenville (see 7 above) (ii) 1st cousin 7xremoved of William Wyndham Grenville (see 16 above) (iii) 1st cousin 1xremoved of William Robert Ferdinand Mount, 3xgreat-grandson of Sir Robert Peel (see 24 above). William Robert Ferdinad Mount is also the 6xgreat-great-nephew of Robert Bruce, who married Frances Blackett. (iii) husband of Samantha Gwendoline Sheffield, 6xgreat-granddaughter of Lady Caroline Cavendish, 3xgreat-great-aunt of Lady Ada Charlotte Godolphin Osborne, 5xgreat-granddaughter of Elizabeth Blackett. Lady Caroline Cavendish was also the grandmother of Lady Caroline Ponsonby, wife of William Lamb, 2nd Viscount Melbourne, (see 23 above).
54. Theresa May 2016-2019 Conservative – no link found.
55. Boris Johnson 2019-2023 Conservative. 13th cousin 20xremoved of Alice Tempest, husband of Nicholas Blackett of Woodcroft.
56. Liz Truss 2023 Conservative - no link found.
57. Rishi Sunak 2023- Conservative - no link found.