From that well-known encyclopædia:-
Building of Castle Howard began in 1699 and took over 100 years to complete to a design by Sir John Vanbrugh for the 3rd Earl of Carlisle. The site was that of the ruined Henderskelfe Castle, which had come into the Howard family in 1566 through the marriage of Thomas, 4th Duke of Norfolk to Elizabeth Leyburne, widow of Thomas, 4th Baron Dacre. For the Duke of Norfolk’s son Lord William Howard had married his step-sister Elizabeth Dacre, the daughter of the 4th Baron Dacre who brought with her the sizeable estates of Henderskelfe and Naworth Castle as well.
The house is surrounded by a large estate which, at the time of the 7th Earl of Carlisle, covered over 13,000 acres and included the villages of Welburn, Bulmer, Slingsby, Terrington and Coneysthorpe.The estate was served by its own railway station, Castle Howard, from 1845 to the 1950s.