Born at Vienna, Seaham was the second son of Charles William Stewart, third marquess of Londonderry, an army officer and diplomatist who through his marriage to his second wife, Frances Anne Vane, had acquired the family’s extensive coal interests in county Durham.
At the 1847 general election Seaham was brought forward by his father for Durham North. Londonderry, a belligerent opponent of Reform who had established the Durham Conservative Association in 1833 and held its purse strings thereafter, believed that his ‘great sacrifice and strenuous exertions for the Conservative cause in the country’ entitled him to ‘a right to look’ at his son’s ‘claims to representation as above those of all others’.
For all his father’s efforts to secure his return, Seaham made little impact in the Commons. In his first Parliament, he is not known to have made any speeches and was far from a regular presence in the division lobbies.
At the 1852 general election Seaham offered again as an ‘independent supporter’ of Derby and was returned unopposed.
On the death of his father, 6 Mar. 1854, Seaham succeeded as earl Vane and assumed the additional surname of Tempest by royal licence, 28 June 1854. Elevated to the Lords, he rarely intervened in debate. In 1867 he embarked on a special mission to St. Petersburg to invest the Emperor Alexander II with the Order of the Garter, and in return, he received the Grand Cross of St. Alexander Newski.
