His eldest son, the fifth marquess, was also a Conservative politician. In 1941 he was summoned to the House of Lords through a writ of acceleration in his father's junior title of Baron Cecil. During his career Lord Salisbury notably held office as Paymaster-General, Secretary of State for the Dominions, Secretary of State for the Colonies, Lord Privy Seal and Leader of the House of Lords. He was an opponent of attempts to reform the House of Lords but was forced to see the Parliament Act 1949 even further limit the power of the House of Lords. However, Lord Salisbury was also behind the Salisbury Convention of 1945, which states that the House of Lords shall not oppose the second reading of any government legislation promised in its election manifesto.