Earl of Mornington used as a courtesy title by the heir apparent to the Marquess of Douro, himself the heir apparent to the Duke of Wellington. As of 2015 the title is held by courtesy by Arthur Wellesley, Earl of Mornington, son of Arthur Wellesley, Marquess of Douro and grandson of Charles Wellesley, 9th Duke of Wellington. The Wesley or Wellesley family descended from Sir Richard de Wellesley (15th century). His grandson Sir William Wellesley (died 1602) lived at Dangan Castle, County Meath. The family estates passed down the male lines. One of Wellesley's daughters, Alison, married John Cusack. Their son Sir Thomas
Richard Wellesley, 6th Earl Cowley Lord Cowley married Maria, daughter of Enrique Buenaño, in 1971. They had two daughters. He died in December 1975, aged only 29. As he had no sons he was succeeded in the earldom by his uncle Garret Wellesley. Richard Wellesley, 6th Earl Cowley Richard Francis Wellesley, 6th Earl Cowley (12 June 1946–13 December 1975), known as Viscount Dangan from 1962 to 1968, was a British Conservative politician. Cowley was the only son of Denis Arthur Wellesley, 5th Earl Cowley, and his first wife Elizabeth Anne (née Papillon), and was educated at Eton. He succeeded in the earldom on his father's