Fenian movement (fē´nēən) or Fenians, secret revolutionary society organized c.1858 in Ireland and the United States to achieve Irish independence from England by force. It was known variously as the Fenian Brotherhood, Fenian Society, Irish Republican Brotherhood, and Irish-American Brotherhood. The name derives from the ancient Irish Fenians, a professional military corps that roamed over ancient Ireland (c.3d cent.) in the service of the high kings. They figure in the legends that developed around Finn mac Cumhail and Ossian.
The famine of the 1840s brought to a crisis Irish discontent with English rule, culminating in the abortive Young Ireland uprising of 1848, led by William Smith O'Brien. Vast numbers of embittered Irishmen emigrated to the United States, Australia, South America, and Canada, where they redoubled their agitation against England. John O'Mahony, one of those revolutionists driven abroad in 1848, was the organizer of the movement in the United States, and it was he who gave the society its name.
In Ireland the movement was led by James Stephens (1825–1901), who founded the party organ, the Irish People, in Dublin in 1863. The movement made its chief appeal to artisans and shop assistants rather than to the agrarian population. The opposition of the Roman Catholic Church to the society doubtless kept many potential members from joining its ranks. As the movement became stronger and rumors of actual plots arose, the British government took steps to crush it. In 1865 the Irish People was suppressed and Stephens was arrested, although he escaped to America. In 1866 the Habeas Corpus Act was suspended in Ireland, and many Fenians were imprisoned. Initiative shifted to America, where a huge store of arms and money had been accumulated by the Fenians, and where many Irish-American Civil War veterans were eager to strike a blow against England. In 1867 a ship, renamed Erin's Hope, was outfitted and sailed to Ireland, but the Fenians aboard were captured in their attempt to land. In the same year there were several small-scale risings in Ireland. Repeated attempts by the revolutionists to free their imprisoned comrades by force resulted in the execution of several Fenians. Agitation continued, and terrorism was condoned by many as a result of the anger aroused by the executions. The long-range effect of the Fenian movement was to draw the attention of the English Parliament to Irish problems. The Fenian movement continued until World War I, but its influence was largely drawn off into new organizations, notably Sinn Féin, founded by Arthur Griffith, a former Fenian.
In the United States
The Fenian movement in America had a career of its own. In 1865 a convention at Cincinnati determined upon an invasion of Canada. In June, 1866, Gen. John O'Neill (1834–78) with about 800 men crossed the Niagara River and captured Fort Erie. His force was soon cut off by U.S. troops, and he was obliged to retreat toward Buffalo. Some 700 men were arrested. An attack on Campobello island (off Maine) was also frustrated. O'Neill became president of the society and prepared raids from Vermont in 1870. These, too, were unsuccessful, and O'Neill and many other participants were arrested.
See studies by J. O'Leary (1896, repr. 1969), W. D'Arcy (1947, repr. 1971), and B. Jenkins (1969).