All that remained of his ambitions was Castle Coole itself, and that was really more a source of satisfaction to posterity than to himself, for he effectively handed over his various properties to his son and heir, Somerset, on his coming-of-age in 1795.
His ambitions were fulfilled by leaving behind only Castle Coole, which brought more satisfaction to the historical record than to him personally, as he gave all of his other possessions to his son, Somerset, when he reached adulthood in 1795.