Historically, this Spanish dukedom is held by the successors of the 1st Duke of Wellington holding the title of Duke of Wellington, although this has not always been the case because of different succession laws. Traditionally, when titles were created, the first holder could determine how their title would pass: in the United Kingdom, almost all ducal titles were created with agnatic primogeniture, while Spanish titles usually passed either by male primogeniture or by agnatic primogeniture. This changed with the 2006 reform to Spanish nobility succession, which enforced succession by absolute primogeniture to all titles.
In 2010, The 8th Duke of Wellington & 9th Duke of Ciudad Rodrigo ceded the Spanish dukedom to his eldest child, Charles Wellesley, Marquess of Douro, who, in accordance with Spanish procedure, made formal claim to the title with the Spanish authorities on 10 March 2010.[2]King Juan Carlos of Spain, through his minister, granted the succession of the dukedom to the Marquess of Douro by Royal Decree of 21 May 2010.[3] The new Duke of Ciudad Rodrigo succeeded his father as Duke of Wellington in 2014.
As of 2024[update] the heir apparent to the Dukedom of Ciudad Rodrigo is the 10th Duke's eldest child, Arthur Wellesley, Earl of Mornington. Lord Mornington has fraternal twins, a first-born daughter, Lady Mae Madeleine Wellesley, and a second-born son, Arthur Darcy Wellesley, Viscount Wellesley. Lady Mae Madeleine is Lord Mornington's heir apparent to the Spanish dukedom as the eldest child, while Viscount Wellesley is the heir to the British dukedom as the eldest male, which could lead to another separation of these titles.
Richard Wellesley 1760–1842 Marquess Wellesley, 2nd Earl of Mornington and Viscount Wellesley, 3rd Baron Mornington, Baron Wellesley
William Wellesley-Pole 1763–1845 3rd Earl of Mornington and Viscount Wellesley, 4th Baron Mornington, 1st Baron Maryborough
Arthur Wellesley 1769–1852 1st Duke of Wellington, Duke of Victoria, Prince of Waterloo, Duke of Ciudad Rodrigo, Marquess of Wellington, Marquess of Torres Vedras, Marquess Douro, Viscount Wellington, and Baron Douro
Marquessate Wellesley and Barony Wellesley extinct, 1842
Arthur Richard Wellesley 1807–1884 2nd Duke of Wellington, Duke of Victoria, Prince of Waterloo, Duke of Ciudad Rodrigo, Marquess of Wellington, Marquess of Torres Vedras, Marquess Douro, Viscount Wellington, and Baron Douro, 6th Earl of Mornington and Viscount Wellesley
Henry Wellesley 1846–1900 3rd Duke of Wellington, Duke of Victoria, Prince of Waterloo, Duke of Ciudad Rodrigo, Marquess of Wellington, Marquess of Torres Vedras, Marquess Douro, Viscount Wellington, and Baron Douro, 7th Earl of Mornington and Viscount Wellesley
Arthur Charles Wellesley 1849–1934 4th Duke of Wellington, Duke of Victoria, Prince of Waterloo, Duke of Ciudad Rodrigo, Marquess of Wellington, Marquess of Torres Vedras, Marquess Douro, Viscount Wellington, and Baron Douro, 8th Earl of Mornington and Viscount Wellesley
Barony Maryborough extinct, 1863
Arthur Charles Wellesley 1876–1941 5th Duke of Wellington, Duke of Victoria, Prince of Waterloo, Duke of Ciudad Rodrigo, Marquess of Wellington, Marquess of Torres Vedras, Marquess Douro, Viscount Wellington, and Baron Douro, 9th Earl of Mornington and Viscount Wellesley
Gerald Wellesley 1885–1972 7th Duke of Wellington, Duke of Victoria, Prince of Waterloo, Duke of Ciudad Rodrigo, Marquess of Wellington, Marquess of Torres Vedras, Marquess Douro, Viscount Wellington, and Baron Douro, 8th Duke of Ciudad Rodrigo, 10th Earl of Mornington and Viscount Wellesley
Henry Valerian George Wellesley 1912–1943 6th Duke of Wellington, Duke of Victoria, Prince of Waterloo, Duke of Ciudad Rodrigo, Marquess of Wellington, Marquess of Torres Vedras, Marquess Douro, Viscount Wellington, and Baron Douro, 11th Earl of Mornington and Viscount Wellesley
Arthur Valerian Wellesley 1915–2014 8th Duke of Wellington, Duke of Victoria, Prince of Waterloo, Marquess of Wellington, Marquess of Torres Vedras, Marquess Douro, Viscount Wellington, and Baron Douro, 9th Duke of Ciudad Rodrigo, 12th Earl of Mornington and Viscount Wellesley
Arthur Charles Valerian Wellesley b. 1945 9th Duke of Wellington, Duke of Victoria, Prince of Waterloo, Marquess of Wellington, Marquess of Torres Vedras, Marquess Douro, Viscount Wellington, and Baron Douro, 10th Duke of Ciudad Rodrigo, 13th Earl of Mornington and Viscount Wellesley