George Vane-Tempest, 5th Marquess of Londonderry

George Henry Robert Charles William Vane-Tempest, 5th Marquess of Londonderry, KP (26 April 1821 – 6 November 1884), styled Viscount Seaham between 1823 and 1854 and known as The Earl Vane between 1854 and 1872, was a British aristocrat, businessman, diplomat and Conservative politician.

Background and education
Born George Vane, he was the eldest son of Charles Vane, 3rd Marquess of Londonderry, by his second wife Frances Anne, daughter and heiress of Sir Henry Vane-Tempest, 2nd Baronet. He was the nephew of the second Marquess, better known as the statesman Lord Castlereagh, and the half-brother of the fourth Marquess. He was educated at Eton and Balliol College, Oxford. He became known by the courtesy title Viscount Seaham in 1823 when his father was created Earl Vane and Viscount Seaham, with remainder to his sons by his second wife.

Political and diplomatic career
Viscount Seaham entered the 1st Life Guards, purchasing a lieutenancy on 7 February 1845, and retiring on 5 May 1848. He was returned to parliament for Durham North in 1847, a seat he held until 1854, when he succeeded his father as Earl Vane and entered the House of Lords. In 1867 he was sent on a special mission as Envoy Extraordinary to Russia to Emperor Alexander II, to invest the emperor with the Order of the Garter.

When his half-brother died childless in 1872 he inherited the marquessate and family estates. Two years later he was appointed a Knight of the Order of St Patrick. In 1880 he became Lord-Lieutenant of County Durham, a post he held until his death four years later.

He was appointed Lieutenant-Colonel Commandant of the 2nd (Seaham) Durham Artillery Volunteer Corps on 26 March 1864. This was a part-time unit largely recruited from his family's Seaham Colliery, and his younger brother and later two of his sons also became officers in the unit. He was succeeded in the command by his eldest son in 1876.

Business interests
Lord Londonderry managed his father-in-law's estates (see below), which included some of the slate quarries around Corris, and was one of the original promoters of the Corris Railway, created to carry the slate from the quarries to the markets. He sat on the board of the Cambrian Railways, latterly as Chairman. He owned lead mines at Van near Llanidloes and was a supporter of the Van Railway which connected the mines to the Cambrian Railways mainline at Caersws.

Family
Lord Londonderry married Mary Cornelia Edwards, daughter of Sir John Edwards, 1st Baronet, on 3 August 1846. They set up home at Plas Machynlleth, the Edwards family seat, and had six children:
 * Charles Vane-Tempest-Stewart, 6th Marquess of Londonderry (1852–1915)
 * Lord Henry John Vane-Tempest (1 July 1854 – 28 January 1905)
 * Lord Herbert Lionel Henry Vane-Tempest (6 July 1862 – 26 January 1921) chairman of the Cambrian Railways, killed in the Abermule train collision
 * Lady Frances Cornelia Harriet Vane-Tempest (c.1851 – 2 March 1872)
 * Lady Alexandrina Louise Maud Vane-Tempest (8 November 1863 – 31 July 1945), married Wentworth Beaumont, 1st Viscount Allendale
 * Lady Avarina Mary Vane-Tempest (c. 1858 – 26 June 1873)

Lord Londonderry died in November 1884, aged 63, and was succeeded by his eldest son, Charles.

The Marchioness of Londonderry remained in residence at Plas Machynlleth, where she entertained Princess Alexandra, the Princess of Wales, in 1897. Lady Londonderry died in September 1906.

The sixth Marquess left Machynlleth on succeeding to the marquessate, but Lord Herbert Vane-Tempest remained resident at the Plas, and also served as Chairman of the Cambrian Railways, until he was killed in the Abermule train collision. The family gave the Plas to the townspeople after World War II.

The sister of the 5th Marquess, Lady Frances Anne Emily Vane (1822–1899) married John Spencer-Churchill, 7th Duke of Marlborough, and was the mother of Lord Randolph Churchill and grandmother of Winston Churchill. On Lord Herbert's death without issue a trust set up by his grandmother Frances Anne passed to Winston, his first cousin once removed, enabling him to purchase Chartwell.