The Wyndham Land Act was the most important land reform introduced by any British government during the period of the Act of Union (1801–1922); and this article provides a new interpretation of the origins of this revolutionary legislation. Whereas previous accounts attribute the Act to the initiative of the Irish chief secretary, George Wyndham, this article locates the legislation in the wider context of both popular and ‘high’ politics. The state of the land question in fin de siècle Ireland is examined, as is the United Irish League's extensive agitation for compulsory land purchase between 1901 and 1903. Finally, the impact of the agitation on the British government is considered, and the article demonstrates that the Wyndham Land Act was introduced as a result of the United Irish League's campaign for land reform.