Ultimately, this erosion of power led to the Parliament Act 1911, which marginalised the Lords' role in the legislative process and gave further weight to the convention that had developed over the previous century that a prime minister cannot sit in the House of Lords. The last to do so was Robert Gascoyne-Cecil, 3rd Marquess of Salisbury, from 1895 to 1902. Throughout the 19th century, governments led from the Lords had often suffered difficulties governing alongside ministers who sat in the Commons.