This article originally appeared in the September 2013 issue of ELLE DECOR. For more stories from our archive, subscribe to ELLE DECOR All Access.Often described as the most beautiful house in Ireland, Russborough is certainly the longest: Its granite facade stretches 700 feet. Designed by German-born architect Richard Castle, the Palladian building dates from the 1740s and was commissioned by Joseph Leeson, whose father had made a fortune in brewing and property speculation.On coming into his inheritance, Leeson decided to buy himself both a seat in parliament and a seat in the country, in County Wicklow. Soon Russborough was filled with treasures acquired during Leesons two Grand Tours across mainland Europe. The rooms in which these were displayed offer outstanding examples of 18th-century Irish craftsmanship, with mahogany parquet flooring and elaborate plasterwork covering ceilings and even wallsall on shining display since 1978, when the property first opened to the public.James FennellThe George II console in the drawing room is flanked by a pair of 1794 chairs, the plasterwork is Baroque, and the 18th-century seascape is one of a quartet by Claude-Joseph Vernet.As befitted the owner of such a house, Leeson decided to acquire a title, becoming Earl of Milltown in 1763. Two decades later he died, in the words of a contemporary, extremely rich, an old debauchee.His successors were, without exception, less colorful: The death of the seventh and final Earl of Milltown, in 1891, went almost without notice. At the start of the 20th century, Russborough passed into the hands of a distant Leeson relative who preferred to remain in England. Eventually the estate was acquired by Colonel Denis Daly, and it remained in his familys possession until 1952. That August an advertisement in Country Life magazine heralding the sale of the historic property was spotted by Sir Alfred Beit, who had long been interested in the estate. Together with his wife, Clementine, a first cousin of the famous Mitford sisters, Beit restored not just the fabric but also the spirit of the old house, replenishing its rooms with glorious paintings, such as the only Vermeer then still in private hands, along with works by Goya, Velzquez, Rubens, Frans Hals, and Gainsborough. James FennellIn the dining room, 20th-century lacquer-and-parcel-gilt chairs in the style of Giles Grendey surround an 18th-century mahogany table; the gilt-wood consoles, attributed to William Kent, are from the same period, the Louis XIV tapestry depicts formal gardens, and the walls are hand-tinted with casein paint.The Beits were glamorous, and their parties and entertaining were legendary, chronicled in a succession of fat leather-bound albums. English historian John Julius Norwich, a regular guest, recalls evenings in the dining room complete with superb silver, the Waterford glass, the tall candles, and, as I remember, at least two liveried footmen in blue tailcoats, yellow waistcoats, and shining brass buttons. Overseeing the ceaseless festive activities was John Pollard, Russboroughs butler for more than 40 years. Among the Beit papers are Pollards daily instructions from Sir Alfred tactfully advising on the idiosyncrasies of individual guests, as well as indicating the correct pronunciation of names and titles. James FennellIn the tapestry room, the English State bed and settees, all covered in matching silk, were made in 1794 by Wilsons of the Strand; the mahogany-and-brass center table is Regency.The Beits had no children and, in 1976, established a charitable trust to ensure that the landmarks future would never again be in doubt. Sir Alfred died in 1994, his wife 11 years later. Their finest paintings were donated to the National Gallery of Ireland; some others were stolen (and recovered) in a series of robberies. But a majority of the works remain in placealong with exquisite pieces of furniture, tapestries, silver, and porcelainas they have been for more than 250 years.Tour this grand 18th-century estate in IrelandThis story originally appeared in the September 2013 issue of ELLE DECOR.