21 April] 1745 – 13 February 1818), styled Lord Gowran from 1751–8, was an Anglo-Irish peer, soldier, and member of parliament.

[5] In 1794, he was given the title of Baron Upper Ossory, of Ampthill in the County of Bedford, in the Peerage of Great Britain, which gave him a seat in the House of Lords.

While in Europe in the early 1763, Ossory met Horace Walpole, who in 1766 introduced him to the unhappily married Anne FitzRoy, Duchess of Grafton, the wife of the philandering Augustus Fitzroy, 3rd Duke of Grafton (who fathered 16 illegitimate children in his lifetime).

[7][8] In August 1768, the Duchess of Grafton gave birth to Ossory's daughter, also named Anne.

The Duke of Grafton, who that fall assumed the role of Prime Minister, sued her for divorce on the grounds of adultery.

As divorcées were not allowed in the Royal Court, the Countess of Upper Ossory rarely went to London and lived a quiet life at Ampthill.

[2] Some of his estates in England, including Ampthill Park, were inherited by his nephew Henry Vassall-Fox, 3rd Baron Holland.

[3] Ossory had three daughters with Anne Liddell: He had three illegitimate children with Elizabeth Wilson, who were all baptised by Rev.