The titles of Duke of Wellington and Marquess Douro were bestowed upon Arthur Wellesley, 1st Marquess of Wellington, on 3 May 1814 after he returned home a hero following Napoleon's abdication. He fought some sixty battles during his military career. He was considered "the conqueror of Napoleon". He stands as one of the finest soldiers that Great Britain and Ireland has ever produced, others being the 1st Duke of Marlborough and the 2nd Duke of Argyll. The subsidiary titles of the Duke of Wellington are Marquess of Wellington, Marquess Douro, Earl of Mornington, Earl of Wellington, Viscount Wellesley, Viscount Wellington, Baron Mornington, and Baron Douro. The Viscountcy of Wellesley and the Barony and Earldom of Mornington are in the Peerage of Ireland; the rest are in the Peerage of the United Kingdom. Apart from the British titles, the Dukes of Wellington also hold the titles of Prince of Waterloo of the Kingdom of the Netherlands, Duke of Ciudad Rodrigo of the Kingdom of Spain, and Duke of Victoria, with the subsidiary titles Marquess of Torres Vedras and Count of Vimeiro of the Kingdom of Portugal. These were granted to the first Duke as victory titles for his distinguished service as victorious commanding general in the Peninsular War and at the Battle of Waterloo. The family seat is Stratfield Saye House, near Basingstoke, Hampshire. Apsley House, in London, is now owned by English Heritage, although the family retain an apartment there.
Should the direct male line of succession from the first Duke of Wellington become extinct, the dukedom and its subsidiary titles in the British peerage will become extinct, as will the titles of Prince of Waterloo in the Dutch peerage and the dukedom of the Victory and its subsidiary titles in the Portuguese peerage. The dukedom of Ciudad Rodrigo in the Spanish peerage, together with its subsidiary titles, will continue to be held in the female line of descendants of the first Duke. The earldom and barony of Mornington, along with the viscountcy of Wellesley, which are all titles in the Irish peerage, will revert to the line of the Earl Cowley, a male-line descendant of a younger brother of the first Duke of Wellington. The Colley or Cowley family had come to Ireland from Glaston, in Rutland about 1500; Sir Henry Colley was elevated to the Peerage as Lord Glaston by Henry VIII. He married the daughter of Thomas Cusack, Lord Chancellor of Ireland, Catherine Wellesley Cusack whose grandmother was a Wellesley. Upon the death of his cousin Garret Wesley and his inheritance of the Estates of Dangan and Mornington, Richard Colley and his wife Elizabeth Sale daughter of John Sale, Registrar of the Diocese of Dublin, on 23 December 1719. adopted the name Wellesley and through her Husband's Family, his cousin, Garret Wesley.