The Parliament Act 1911 is a short act of parliament, which had a profound effect on constitutional and political legislation in the 20th century. The purpose of the Parliament Act was very clear: to limit the power of the house of lords to impede the programme of a government with a majority in the house of commons. The act achieved this by introducing three innovations: (1) it put on the statute book the primacy of the house of commons over financial legislation; (2) the house of lords' absolute veto over legislation in most areas was replaced by a suspensory veto of approximately two years; (3) the act reduced the maximum duration of a parliament from seven years to five. But at the start of the parliament, in 1906, it was not clear that this programme would prevail: its enactment over alternative proposals was helped by a combination of the leadership of Campbell-Bannerman and Asquith, political conflict, electoral and parliamentary arithmetic, and the politics of the Irish question. The Parliament Act fundamentally and irreconcilably altered the legislative process in the United Kingdom, whilst arguably leaving the de facto constitutional position unchanged. In doing so, it facilitated a century of constitutional legislation.