Fitzgerald, James (1722–73), 20th earl of Kildare and 1st duke of Leinster , politician, was born 29 May 1722 in Dublin, second son of Robert Fitzgerald (1675–1744), 19th earl of Kildare, and his wife Mary (d. 1780), eldest daughter of William O'Brien, 3rd earl of Inchiquin. He was educated at home before travelling on the Continent from 1737 to 1739. The next year he became heir to the earldom and estates on the death of his brother, and on 20 February 1744 he succeeded his father as 20th earl of Kildare.
His political career began on 17 October 1741, when (then known as Lord Offaly) he entered the Irish house of commons as member for Athy. The turbulence of his political career was hidden in peaceful and overtly loyal beginnings. In 1744 he moved to the house of lords as the premier earl in the country and one of the most powerful borough patrons. Mindful of his duty to protect protestant Ireland against Jacobite threats, Kildare offered to raise a regiment at his own expense in 1745. The viceroy, Lord Chesterfield (qv), did not take up this offer but Kildare's popular reputation was established, especially in Dublin and the surrounding counties. On top of this popularity the earl had powerful electoral interests, particularly in Co. Kildare and Co. Carlow, and returned or influenced between twelve and fifteen MPs. His seniority in the peerage, popularity, and electoral interests ensured his appointment to the privy council (12 May 1746). He was made an English peer, Viscount Leinster of Taplow, Bucks. (1 February 1747), and appointed lord justice (11 May 1756). Master general of the ordnance (1758–66), he became major-general (11 November 1761) and lieutenant-general (30 March 1770). He was also promoted through the Irish peerage, becoming marquis of Kildare (19 March 1761) and duke of Leinster (26 November 1766).
Kildare really exploded into the limelight during the crisis of the Dorset (qv) years. The earl, after Dorset's first parliamentary session in 1751–2, moved into open opposition to government. He went to London in June 1753 to demand an audience with George II and present a memorial asking for Dorset's removal. The mission was both a disaster and a triumph. Kildare embarrassed his Fox and Lennox relatives with his uncompromising style, which the ministry rebuked, but he returned to Dublin in July to a hero's welcome. This may have been the moment when a local crisis of parliamentary management became an Anglo–Irish one. Historians once saw Kildare as pursuing an intermediary course between the Patriots of the speaker, Henry Boyle (qv), and the Castle forces led by Dorset and Archbishop Stone (qv). This is no longer accepted, as the earl once more chose to defend Ireland, this time from corrupt ministers and economic ruin. His supporters, led by Anthony Malone (qv), demanded an absentee tax in October 1753 and then asserted the absolute right of the Irish parliament to control Irish finances. This ruled out a compromise on the king's previous consent for the use of an Irish treasury surplus. In reality, it was Kildare and his lieutenants who successfully pushed for the rejection of a minor supply bill on 23 December 1753, which led to the proroguing of the session the following month.
Kildare's position as a leading Patriot was further consolidated when he repeated his mission to London in April 1754 with an even stronger memorial, asserting the rights of the Irish parliament and demanding the sacking of both Dorset and Stone. Henry Fox managed to keep him away from the king but he was fêted in Dublin and had a medal struck in his honour. Dorset's successor, Lord Hartington (qv), focused on Kildare as the key to ending the crisis. Thus, his demands concerning Stone and ‘previous consent’ were both met in the deal of 1756 and he escaped public odium by not taking government rewards as others had done. Instead, Kildare served as lord justice from May 1756 to September 1757 and hoped he might become sole lord deputy. However, the factious opposition that he saw himself as avoiding in 1752–5 triumphed as both Stone and Boyle (now Lord Shannon) were restored to government. Kildare refused to accept this outcome and was never again considered as a lord justice after 1758.
The decade of the 1760s were much more rewarding for Kildare, in terms of offices and his dukedom, but his political career was basically over. In the military offices he showed more enthusiasm than sense, and his repeated quarrels with Irish generals meant that his resignation in May 1765 was greeted with some relief. In the political sphere Kildare remained a major force, though never a reliable undertaker of government business. However, he was prepared to support the Castle, as in December 1760 when he opposed the opinion of almost all Irish politicians in proposing that the privy council draft a supply bill for a new parliament. Though his own allies (Malone, for example) disagreed with him, Kildare saw his stance as consistent with his earlier patriotism, in defiance of factious electioneering. Despite this action, for which he was almost certainly rewarded with the dukedom (1766), he was still regarded by government as a loose cannon, quite capable of demanding a viceroy's dismissal, as he did in 1771 to Lord Townshend (qv). Therefore, it is not easy to assess his political ambitions, although some contemporaries believed he wanted to be lord lieutenant to restore the historic position of the Fitzgeralds. Ultimately, however, he lacked flexibility and his career was littered with acts of principle or pique, which were to dog his relationship with successive viceroys.
When he was still Lord Kildare he married (7 February 1747) Lady Emily Lennox, second daughter of Charles, 2nd duke of Richmond, and sister-in-law to Henry Fox. This happy marriage brought him nineteen children and a wife who proved both astute and influential. On several occasions she successfully prevented Kildare from resigning office and she also persuaded him to complete work on Carton House. The pair then turned to building a fine Georgian house on Dublin's Kildare St. (latterly the seat of both houses of the oireachtas). All of this came at a cost, as he left debts of £148,000 and, after providing generously for Emily and the surviving children, his heir was said to be left only £7,000 a year. Leinster died on 19 November 1773 at Leinster House, Dublin, and was buried in Christ Church cathedral four days later. His papers are principally divided between the NLI and the PRONI.