The Hills had become well established by the end of the 17th century, and most of them were eminent public figures, members of the Irish parliament and Privy Council. Wills Hill, who succeeded his father Trevor Hill, 1st Viscount Hillsborough in 1742, was the most distinguished public figure in the family's history. Like his father Governor of the county and an Irish Privy Councillor, he was known as courtier and politician on a wider stage, serving in several of George III's early ministries, notably at the Colonial Office during a crucial period in relations between the king and his American subjects. Successive steps in the peerages of Great Britain and Ireland were crowned in 1789 by the title of Marquess of Downshire in the Irish peerage. Apart from the estates at Blessington and Loughbrickland which came to him by inheritance, he established the nucleus of the Banbridge estate by purchasing four townlands in 1749 from Richard Whyte. The subsequent growth of Banbridge as a centre of the linen trade was greatly fostered by the new landlord's encouragement, an encouragement also exercised on a national scale as a member of the Linen Board. A man of some taste and culture, Wills Hill was responsible for rebuilding the mansion at Hillsborough, along with the parish church and most of the village. He died in 1793. Family fortunes declined after 1845, rents were reduced after application of the Land Act in 1881 and the estates were largely dissolved under the later land acts at the beginning of the 20th century.