As the couple had no children, the inheritor was William's godson and grand-nephew, William Wellesley, son of the first earl of Mornington and elder brother of the Duke of Wellington. To accept the inheritance, William was bound to assume the Pole surname, so he changed his name to William Wellesley-Pole. William became the first Baron Maryborough and later the third earl of Mornington. Rather than leaving the estate to his spendthrift son, who ultimately died penniless after squandering his wife's massive fortune, William Wellesley-Pole sold Ballyfin to Sir Charles Henry Coote, the premier Baronet of Ireland. Sir Coote and his wife added further extensions to the house, first with the notorious Dominick Madden and later by the efforts of Morrisons, Richard and his son William Vitruvius, who broke down Madden's work as part of their plans. The new design included tall columns, mahogany doors and bookcases, exotic parquet floors, and Roman mosaic set into the entrance hall's stone floors. The Coote family retained control of the property for over a century but were ultimately forced to sell upon losing the estate to the Land Commission.
The Patrician Brothers, a religious order, bought the estate for only 10,000 pounds sterling and used it as a boarding school. They put it up for sale in 2001. At the time, it was considered barely habitable, having suffered water damage. A great deal of work was required to return it to a decent condition. Even the grounds had suffered from a lack of upkeep, and sections of the woodland needed to be replanted entirely. The new owners undertook the challenge of restoring the house and parklands to their former glory, while trying to keep the house as close to its original plan as possible. Work carried on from 2002 to 2010, after which Ballyfinwas opened to the public as a luxury hotel
. In homage to the previous owners and highlighting the estate's history, each of the rooms has been named for the various original owners of the estate.Castle Durrow
is an 18th-century country house built by an AngloIrish landlord, Colonel William Flower. The current building is still quite close to its original state. The Flower family, who were Barons and Viscounts Ashbrook, occupied the castle in 1716, four years after construction began but expansions and improvements continued unimpeded over the course of two centuries. They were known as benevolent landlords and were the largest employers of Durrow Village.