Curran is the eldest of five children of James Curran, seneschal of the Newmarket manor court, and Sarah, née Philpot. The Curran family are said to have originally been named Curwen, their ancestor having come from Cumberland as a soldier under Oliver Cromwell during the Cromwellian conquest of Ireland, originally settling in County Londonderry.
Curran is educated at Midleton College, County Cork, before studing law at Trinity College Dublin. He continues his legal studies at King’s Inns and the Middle Temple. He is called to the Irish Bar in 1775. Upon his first trial, his nerves get the better of him and he cannot proceed. His short stature, boyish features, shrill voice and a stutter are said to have impacted his career, and earn him the nickname “Stuttering Jack Curran.”
However, Curran can speak passionately in court on subjects close to his heart. He eventually overcomes his nerves and gets rid of his speech impediment by constantly reciting Shakespeare and Bolingbroke in front of a mirror, becoming a noted orator and wit. His championing of popular Irish causes such as Catholic emancipation make him one of the most popular lawyers in Ireland. He is also fluent in the Irish language which is still the language of the majority at the time. He writes a large amount of humorous and romantic poetry.
The case which cements Curran’s popularity is that of Father Neale and St. Leger St. Leger, 1st Viscount Doneraile at the County Cork Assizes in 1780. Having a passion for lost causes, he represents the priest and wins over the jury by setting aside the issue of religion.
A liberal Protestant whose politics are similar to Henry Grattan, Curran employs all his eloquence to oppose the illiberal policy of the Government, and also the Union with Britain. He stands as Member of Parliament (MP) for Kilbeggan in 1783. He subsequently represents Rathcormack (1790-98) and Banagher from 1800 until the Act of Union in 1801, which bitterly disappoints him, forcing him to contemplate emigrating to the United States.
In 1798, Ireland rebels against the British House of Commons and lack of reforms on Catholic emancipation. The British defeat the Irish rebels in numerous battles and soon establish their control over the country by 1799. Many of the Irish ring leaders are charged with treason and are facing death sentences. Curran plays an important role in court defending the leaders of the United Irishmen.
Curran’s youngest daughter Sarah‘s romance with United Irishmen leader Robert Emmet scandalises Curran, who had tried to split them up. He is arrested and agrees to pass their correspondence on to Standish O’Grady, 1st Viscount Guillamore, the Attorney-General for Ireland. In the circumstances he cannot defend Emmet. He is suspected of involvement in Emmet’s Rebellion, but is completely exonerated. However, his friend Arthur Wolfe, 1st Viscount Kilwarden, is killed by the rebels, and he loses any faith in the beliefs of the United Irishmen. Emmet is found guilty of rebelling against the Crown and the union between Great Britain and Ireland and is hanged in 1803. Curran disowns Sarah, who dies of tuberculosis five years later.
Curran is appointed Master of the Rolls in Ireland in 1806, following William Pitt the Younger‘s replacement by a more liberal cabinet.
Curran retires in 1814 and spends his last three years in London. He dies in his home in Brompton on October 14, 1817. In 1837, his remains are transferred from Paddington Cemetery, London to Glasnevin Cemetery in Dublin, where they are laid in an 8-foot-high classical-style sarcophagus. In 1845 a white marble memorial to him, with a carved bust by Christopher Moore, is placed near the west door of St. Patrick’s Cathedral, Dublin.