John Bligh, 1st Earl of Darnley, married Theodosia Hyde, 10th Baroness Clifton (of Leighton Bromswold), great-granddaughter of Lord George Stuart, younger son of Esmé Stewart, 3rd Duke of Lennox, also 3rd Earl of Darnley (see the Baron Clifton of Leighton Bromswold and the Duke of Lennox for earlier history of these titles).

In 1828 he presented a claim as heir-general to the dukedom of Lennox, challenged by the Countess Nugent,[5] but the House of Lords did not come to any decision on the matter.

On the death of his grandson, the seventh Earl (who had succeeded his father in 1896), the barony of Clifford of Leighton Bromswold separated from the Irish titles when it devolved upon the late Earl's daughter and only child, the ten-month-old Lady Elizabeth Bligh, who became the seventeenth holder of the barony by writ of summons.

A talented and successful cricketer who captained MCC, he sat in the House of Lords as an Irish representative peer from 1905 to 1927.

Thomas Bligh, younger brother of the first Earl, was a general in the British Army and represented Athboy in the Irish House of Commons for sixty years.

Susan Bligh, Countess of Darnley, the eleventh Earl's wife was appointed Lord Lieutenant of Herefordshire in 2008.

He was descended from a prominent Devon family via a cadet branch which had settled in County Meath, Ireland.

[4] He died in 1728 and was buried with his wife in the "Hyde Vault" in Westminster Abbey, in the north ambulatory, near the steps up to Henry VII's chapel.

He carried out various building works at Cobham, between 1768 and 1770 he added an extra floor to the west front, to the design of Sir William Chambers.

By his will he left instructions for the building of the Darnley Mausoluem within the deer park, to house the embalmed corpses of his descendants, the "Hyde Vault" in Westminster Abbey (in the north ambulatory, near the steps leading up to Henry VII's Lady Chapel[11]) having become full.

Although the work was duly completed in 1786, to the design of the architect James Wyatt, it never received the approval of the local Bishop of Rochester to become a consecrated building and thus was never used for its intended purpose.

He built a bridge connecting the north front to the terrace forming an entrance under a porte-cochere, to the design of James Wyatt.

His daughter Lady Elizabeth Bligh (1830-1914) (wife of Sir Reginald Cust and mother of the courtier Sir Lionel Cust) was a historian and genealogist, who (as "Lady Elizabeth Cust") was the author of Some Account of the Stuarts of Aubigny, in France, London, 1891, dedicated by permission to Queen Victoria and intended "to preserve from oblivion the gallant deeds of the Stewarts of Aubigny who commanded the Scots Guards and Scots Men-at-Arms in the great wars of France from the time of Charles VII to that of Henri IV".

[12][page needed] She also wrote Records of the Cust family of Pinchbeck, Stamford and Belton in Lincolnshire, 1479-1700, 3 vols, 1898.

As "Lord Clifton" he played first-class cricket for Kent 1871-9 and "spent money like water",[15] greatly reducing the wealth of his family.

During the First World War he and his wife set aside the state apartments of Cobham Hall to accommodate 50 Australian officers.

[18] After the War in the 1920s he let Cobham Hall and in 1925 sold the collection of paintings and the outlying estate and converted the eastern deer park into a golf course.

In 1959 following the death of his father and facing heavy inheritance tax demands, he sold the house, gardens and part of the park to the "Land Fund", which sold them on in 1963 to the Westwood Educational Trust Limited (a charity in the form of a private company limited by guarantee without share capital, formed in 1961[21]) which established and operates the school which still occupies the site today.

In 1968 the 10th Earl resided nearby at Puckle Hill, Shorne, near Gravesend, Kent,[22] "a large, robust Arts and Crafts house constructed in 1923".

Formally styled as Lord Clifton of Rathmore from 1980, he was educated at Marlborough College and the University of Edinburgh.