James FitzGerald, 1st Duke of Leinster
Lieutenant-General James FitzGerald, 1st Duke of Leinster, PC (Ire) (29 May 1722 – 19 November 1773), styled Lord Offaly until 1744 and known as The Earl of Kildare between 1744 and 1761 and as The Marquess of Kildare between 1761 and 1766, was an Irish nobleman, soldier and politician. Background. Leinster was the son of Robert FitzGerald, 19th Earl of Kildare, and Lady Mary, daughter of William O'Brien, 3rd Earl of Inchiquin. Career. Leinster was a member of the Irish House of Commons for Athy from 1741 before succeeding his father as 20th Earl  of Kildare in 1744. He was sworn of the Irish Privy Council in 1746 and in 1747, on the occasion of his marriage (see below), he was created Viscount Leinster, of Taplow in the County of Buckingham, in the Peerage of Great Britain, and took his seat in the British House of Lords that same year. From 1749 to 1755 he was one of the leaders of the Popular Party in Ireland, and served as the country's Master-General of the Ordnance between 1758 and 1766, becoming Colonel of the Royal Irish Artillery in 1760. He was promoted to  Major-General in 1761 and to Lieutenant-General in 1770. In 1761 Lord Kildare was created Earl of Offaly and Marquess of Kildare in the Peerage of Ireland and in 1766 he was further honoured when he was made Duke of Leinster, becoming by this time the Premier Duke, Marquess and Earl in the Peerage of Ireland. Family. Leinster married the 15-year-old Lady Emily Lennox (6 October 1731 – London, 27 March 1814), daughter of Charles Lennox, 2nd Duke of Richmond and one of the famous Lennox Sisters, in London on 7 February 1747. She descended from King Charles  II and was therefore a distant fifth cousin of King George III (both of them were descended from King James VI and I). The couple had nineteen children: Leinster died at Leinster House, Dublin, in November 1773, aged 51, and was buried in the city's Christ Church Cathedral. He was succeeded by his second (but eldest surviving) son, William, Marquess of Kildare. The Duchess of Leinster caused a minor sensation by marrying her lover William Ogilvie in 1774, but continued to be known as The Dowager Duchess of Leinster. She had a further three children by him. She died  in London in March 1814, aged 82. Popular culture. In 1999, Irish Screen, BBC America and WGBH produced "Aristocrats", a six-part limited television series based on the lives of Emily Lennox and her sisters. Leinster was portrayed by Ben Daniels.