The title was created in 1816 for
Robert Stewart, 1st Earl of Londonderry. He had earlier represented
County Down in the
Irish House of Commons. Stewart had already been created
Baron Londonderry in 1789,
Viscount Castlereagh, of
Castlereagh in the County of Down, in 1795 and
Earl of Londonderry, of the County of Londonderry, in 1796. These titles are also in the Peerage of Ireland. He was the son of
Alexander Stewart, who had married Mary Cowan, sister and heiress of
Robert Cowan, who gained great wealth as
Governor of Bombay from 1729 to 1737. Alexander was from Ballylawn, a
townland at the south-west corner of
Inishowen in the north of
County Donegal, a
county located in the west of
Ulster in the northern part of
Ireland. However, much of the Stewart family's wealth was based on the estates which came into the family through this marriage. The 1st Marquess was one of the few people to become a Marquess without inheriting any titles prior to the creation. He sat in the
British House of Lords as one of the twenty-eight original
Irish representative peer from 1800 to 1821. He was succeeded by his son from his first marriage to Lady Sarah Seymour. The 2nd Marquess, better known as
Lord Castlereagh (he went by the
courtesy title of Viscount Castlereagh from 1796 to 1821), was a noted statesman and diplomat. Castlereagh is best remembered for his tenure as
Foreign Secretary of the United Kingdom from 1812 to 1822 and played an important role at the
Congress of Vienna of 1814 to 1815. He committed suicide in 1822, one year after succeeding his father in the marquessate. The 2nd Marquess did not follow his father as a Representative Peer into the House of Lords, this permitted him to continue fulfilling his roles in the House of Commons. Castlereagh was succeeded by his half-brother, the 3rd Marquess. He was the only son from the 1st Marquess's second marriage to Lady Frances Pratt, daughter of
Charles Pratt, 1st Earl Camden. He was a General in the Army and like his elder half-brother a prominent politician and diplomat. Lord Londonderry served as
Under-Secretary of State for War and the Colonies from 1807 to 1809, fought in the
Napoleonic Wars and was
Ambassador to Austria from 1814 to 1823. In 1814 he was created
Baron Stewart, of Stewart's Court and Ballylawn in County Donegal, in the
Peerage of the United Kingdom. In 1819 Londonderry married as his second wife
Lady Frances Vane-Tempest (died 1865), daughter and wealthy heiress of
Sir Henry Vane-Tempest, 2nd Baronet, through which marriage substantial estates in
County Durham came into the Stewart family. He assumed the additional surname of Vane on his marriage and in 1823 he was created
Viscount Seaham, of Seaham in the County Palatine of Durham, and
Earl Vane, with remainder to the male issue of his second marriage. These titles are in the Peerage of the United Kingdom. Lord Londonderry was succeeded in the viscountcy of Seaham and earldom of Vane according to the special remainder by his eldest son from his second marriage while he was succeeded in the Irish titles and the barony of Stewart by his son from his first marriage to Lady Catherine Bligh, the 4th Marquess. He died childless in 1872 and was succeeded by his half-brother, the 5th Marquess, who had already succeeded his father as second Earl Vane in 1854. He represented
Durham North in the
House of Commons and served as
Lord-Lieutenant of County Durham. In 1851 the 5th Marquess assumed by Royal licence the additional surname of Tempest. On his death, the titles passed to his eldest son, the 6th Marquess. He was a
Conservative politician and held office in the administrations of
Lord Salisbury and
Arthur Balfour as
Lord-Lieutenant of Ireland, as
Postmaster General, as
President of the Board of Education, as
Lord Privy Seal and as
Lord President of the Council. In 1885 he assumed by Royal licence the additional and principal surname of Stewart. He was succeeded by his son, the 7th Marquess, who was also a Conservative politician. He had a career in both Irish and British politics but is best known for his role as
Secretary of State for Air from 1931 to 1935. Lord Londonderry subsequently gained notoriety for his informal diplomatic contacts with senior members of the German government. He made six visits to Nazi Germany between January 1936 and September 1938 meeting
Adolf Hitler on a number of occasions and sympathising with some of his viewpoints. His wife
Edith Vane-Tempest-Stewart, Marchioness of Londonderry, was an influential society hostess remembered for her close friendship with
Ramsay MacDonald. Lord Londonderry was succeeded by his son, the 8th Marquess. He represented
County Down in the House of Commons as a Conservative from 1931 to 1945. The
heir apparent to the marquessate is styled
Viscount Castlereagh, although the Marquess is also the Earl Vane, and the heir apparent's heir apparent, when such exists, is styled
Lord Stewart. Between 1823 and 1854 and between 1872 and 1999, the Marquesses of Londonderry sat in the
House of Lords as
The Earl Vane. Between 1822 and 1823 and between 1854 and 1872, they sat as
The Lord Stewart. ==Residences==