The son of an Irish farmer who had been evicted from his holding, he opposed the British-imposed land-holding system in Ireland. In 1865 he joined the Irish Republican Brotherhood, a movement committed to the establishment of an independent republic of Ireland. He was sentenced to 15 years’ penal servitude in 1870 for smuggling weapons for the Fenians. Released in 1877 he helped found the Irish Land League in 1879, an organization formed to achieve land reform. With Charles Sewart Parnell, he sought to protect Irish peasants against evictions and high rents. He was elected a Member of Parliament in 1882 while in prison, and again in 1892 and 1895. The agitation that he led influenced Gladstone to introduce the 1881 Irish Land Act, guaranteeing fair rents, fixity of tenure, and freedom to sell (the Three Fs) to tenants.