Charles Stewart Henry Vane-Tempest-Stewart, 7th Marquess of Londonderry (1878-1949) had careers in both Irish and British politics.

First son of the 6th Marquess of Londonderry, he was pressured by his parents to stand for election to the House of Commons at the 1906 General Election (styled by the courtesy title Viscount Castlereagh). His relatively unsucessful career on the depleted Unionist backbenches was broken by a return to the army during the First World War. Hitherto reluctant to involve himself like his father in Irish politics, the War prompted him to take up the cause of recruitment in Ireland. With his father's death in 1915 he inherited not only the Londonderry title, but also the immense wealth and status that went with it. His exalted position helped his political career, not least in Ireland, and this in turn brought him favorable attention at Westminster.

After serving on the Irish Convention of 1917-18, Londonderry served on the shortlived Viceroy's Advisory Council, meeting at Dublin Castle in the autumn of 1918. This was followed by his appointment to the Air Council at Westminster in 1919, as part of the postwar Coalition government. With only a promotion to Under Secretary of State for Air in 1920, Londonderry grew frustrated and took advantage of his Ulster connections to join the first government of Northern Ireland in June 1921, as Leader of the Senate and Minister for Education. At Belfast he acted as a check on the increasingly partisan and survivalist government of Prime Minister James Craig. Nevertheless, Londonderry's Education Act of 1923 received little in the way of good will from either Protestant or Catholic educational interests, and was amended to the point that its purpose, to secularise schooling in Northern Ireland, was lost.

In 1926 he resigned from the Belfast Parliament and involved himself in the General Strike of that year, playing the role of a moderate mine owner, a stance made easier for him by the relative success of the Londonderry mines in County Durham. His performance earned him high praise, and along with the Londonderrys' role as leading political hosts, Lord Londonderry was rewarded by Prime Minister Stanley Baldwin with a seat in the Cabinet in 1928 as First Commissioner of Works. Londonderry was also invited to join the emergency National Government under Prime Minister Ramsay MacDonald and Lord President Baldwin in 1931. This was the cause of some scandal as MacDonald's many critics accused the erstwhile Labour leader of being too friendly with Edith, Lady Londonderry.

When the National Government won the 1931 General Election Londonderry returned to the Cabinet as Secretary of State for Air. This position became increasingly important during his tenure, not least due to the deliberations of the League of Nations Disarmament Conference at Geneva. Londonderry toed the British government's equivocal line on disarmament, but opposed in Cabinet any moves that would risk the survival of the Royal Air Force. For this he was attacked by Clement Attlee and the Labour Party, and thus became a liability to the National Government. In the spring of 1935 he was removed from the Air Ministry but retained in the Cabinet as Lord Privy Seal and Leader of the House of Lords.

After the 1935 General Election Baldwin took the oppotunity to sack him. The sense of hurt Londonderry felt at this, and of accusations that he had misled Baldwin about the strength Nazi Germany's air force, led him to seek to clear his reputation as a 'warmonger' by engaging in amateur diplomacy. This involved visits to senior Nazis in Germany, and briefings with government officials in London. His high profile promotion of 'Anglo-German' friendship, in the end, marked him with a far greater slur than that which had led him to engage in appeasement in the first place. After playing a marginal role in the overthrow of Neville Chamberlain in 1940, he failed to win any favour from his cousin, Prime Minister Winston Churchill. Without office he produced his memoirs, Wings of Destiny (1943), a relatively short book that was considerably censored by his former colleagues.

|- style="text-align: center;" | width="30%" |Preceded by:
George Lansbury | width="40%" style="text-align: center;" |First Commissioner of Works
1931 | width="30%" |Succeeded by:
William Ormsby-Gore

|- style="text-align: center;" | width="30%" |Preceded by:
The Lord Amulree | width="40%" style="text-align: center;" |Secretary of State for Air
1931–1935 | width="30%" |Succeeded by:
The Viscount Swinton