In a 70-year period, the Dukes of Leinster fell from being Ireland's premier aristocratic family, close friends of the British monarchy, secure within the world's most powerful empire, to relative obscurity in an independent Irish Free State that did not recognize titles. And, while in 1872, when this study begins, the 3rd Duke of Leinster resided in some grandeur in the Palladian Carton House, the 7th Duke would die impoverished in a one-room bedsit flat in St. George's Drive, Westminster, London, just over a century later in 1976. The story moves from the small town of Maynooth, County Kildare, to London, to continental Europe, to an asylum in Edinburgh, to the US, before completing the circle and ending back in Maynooth in the 1940s. The narrative of decline and fall unfolds against such historical watersheds as the Land War of the 1880s and the simultaneous rise of the Home Rule movement; the breakup of Irish landed estates after 1903; the Great War of 1914-1918; the revolutionary turmoil of 1916-1923; and the 1920s global economic depression. The impact of such public events as mentioned above has featured prominently in the historiography of the decline of the Irish landed class, both north and south. However, little attempt has been made to combine that history with private lives and experiences. The book sets out to rectify this. In the process, it reveals the tragic personal story of Hermione, 5th Duchess of Leinster, and her three sons, gathered from sources here-to-fore unused by historians of the Leinsters.