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, 1st Marquess Wellesley Wellesley was appointed ambassador to Spain. He landed at Cádiz just after the Battle of Talavera, and tried unsuccessfully to bring the Spanish government into effective co-operation with his brother, who, through the failure of his allies, had been forced to retreat into Portugal. A few months later, after the duel between George Canning and Robert Stewart, Viscount Castlereagh, and the resignation of both, Wellesley accepted the post of Foreign Secretary in Spencer Perceval's cabinet. Unlike his brother Arthur, he was an eloquent speaker, but was subject to inexplicable "black-outs" when he was apparently unaware of his surroundings. He held