This thesis uses Alfred Webb (1834-1908) as a biographical window through which to understand intellectual and political change in late-Victorian Irish so.ciety. Webb's upbringing, by radical Quakers who were deeply involved in the international movement to abolish slavery, gave him a profound dedication to social activism. In 1870 he became an Irish constitutional nationalist and joined the young Home Rule movement, serving as its treasurer for most ofthe subsequent thirty-five years and as an MP from 1890 to 1895. Webb became concerned that Ireland was the only 'colony' within the British Empire to have representation at Westminster, and he became involved in a number of pressure groups to raise the profile of Imperial affairs. In recognition of his services to Indian nationalism, Webb was invited by Dadabhai Naoroji to serve as president ofthe Indian National Congress in 1894. The dissertation is divided into eight chapters that are both chronological and ideological building blocks, and that progress from the local, to the national, to the international level. By studying Webb's politics I have located Irish social and ideological change in a wider transnational movement. My research follows the course of the Home Rule movement, but nationalism does not eclipse the great range of civic and intellectual life that flourished in nineteenth-century Ireland. Most significantly, my re~earch reveals a fascinating and forgotten aspect ofIrish, Indian and British political history: the involvement ofIrish people in the establishment of the Indian nationalist movement.