Henry Welbore Agar-Ellis, 2nd Viscount Clifden, Irish politician styled The Honourable Henry Agar between 1776 and 1789, is born Henry Welbore Agar at Gowran Castle, Gowran, County Kilkenny on January 22, 1761. He is perhaps the only person to sit consecutively in four different Houses of Parliament – the two in Ireland and the two in England.

Agar is the eldest son of James Agar, 1st Viscount Clifden, son of Henry Agar and Anne, daughter of Welbore Ellis, Bishop of Meath, and sister of Welbore Ellis, 1st Baron Mendip. His mother is Lucia, daughter of Colonel John Martin, of Dublin. He is the nephew of Charles Agar, 1st Earl of Normanton.

Agar is returned to the Irish House of Commons for both Gowran and Kilkenny County in 1783, but chooses to sit for the latter, a seat he holds until 1789, when he succeeds his father in the Irish viscountcy and enters the Irish House of Lords. He is appointed Clerk of the Privy Council of Ireland in 1785, which he remains until 1817.

In 1793 Agar is elected to the House of Commons of the United Kingdom as one of two representatives for Heytesbury. He succeeds his great-uncle Lord Mendip as second Baron Mendip in 1802 according to a special remainder in the letters patent. This is an English peerage and forces him to resign from the House of Commons and enter the House of Lords. Two years later he assumes by Royal licence the surname of Ellis in lieu of Agar.

Lord Clifden marries Lady Caroline , daughter of George Spencer, 4th Duke of Marlborough, in 1792. His only son, George, becomes a successful politician and is created Baron Dover in his father’s lifetime, but predeceases his father. Lady Clifden dies at the age of 50 at Blenheim Palace in November 1813. Lord Clifden remains a widower until his death at the age of 75 at Hanover Square, Mayfair, London, on July 13, 1836. He is succeeded in his titles by his grandson Henry, the eldest son of Lord Dover.