The United Irish Society, or United Irishmen, was initially a liberal political organization in eighteenth‐century Ireland that sought parliamentary reform by legal means. It evolved into a radical republican organization with a massive underground army that launched the Great Rebellion of 1798 and aimed at forcefully ending British rule of Ireland and creating an independent republic.

Theobald Wolfe Tone was an Irish nationalist and political writer. He was born in Dublin on June 20, 1763 into a wealthy middle‐class family, but its fortunes declined with a downturn in his father's coach‐building business in the late 1770s. Theobald entered Trinity College in 1781, was suspended briefly for dueling, and graduated in 1786 before going on to train as a barrister. In 1785 he married Matilda Witherington, eloping with her to the disapproval of her family. His career as a barrister commenced in 1789, and in 1790 he began writing pro‐Whig political pamphlets.

James Napper Tandy gained fame as a flamboyant radical during the era of the United Irishmen and the Great Rebellion of 1798. He was born in the late 1730s – the exact year is unknown – into a Protestant family in Dublin; his father was an ironmonger. In adulthood Napper Tandy at first made his living as a land agent and rent collector.

Lord Edward Fitzgerald was born on October 15, 1763 into the highest level of the Irish aristocracy. His father, James Fitzgerald, was the Duke of Leinster, and his mother, Emily, was the daughter of the Duke of Richmond. Lord Edward arrived in Ireland as an infant and was placed in the care of a private tutor, William Ogilvie, who schooled him according to the ultraprogressive educational theories of Jean‐Jacques Rousseau. After the death of his father in 1773 his mother took her children and Ogilvie (her lover) to France.