Vane-Tempest was the son of Charles, 3rd Marquess of Londonderry. As Viscount Seaham, the future Marquess married Mary Cornelia Edwards. Viscount Seaham managedhis father in laws estates, which included some of the slate quarries around Corris, and was one of the original promoters of the Corris Railway. He became Earl Vane on the death of his father, and under that name sat on the board of the Cambrian Railways, latterly as Chairman.