Arthur Blundell Sandys Trumbull Hill, 3rd Marquess of Downshire KP, an Anglo-Irish peer, styled Viscount Fairford from 1789 until 1793 and Earl of Hillsborough from 1793 to 1801, dies on September 12, 1845, in Blessington, County Wicklow.

Hill is born in Hanover Square, on October 8, 1788, the eldest son of Arthur Hill, 2nd Marquess of Downshire, and his wife, Mary Sandys. He becomes Marquess of Downshire on the early death of his father in 1801. He is educated at Eton College and Christ Church, Oxford, gaining his MA in 1809 and a DCL in 1810.

During his early political career, Hill is identified with the Whigs and supports the reform of Parliament. After the Grey Ministry comes to power, he receives a succession of appointments, becoming Colonel of the South Down Militia on March 25, 1831, and carrying the second sword at the coronation of William IV on September 8. He is appointed a deputy lieutenant of Berkshire on September 20, Lord Lieutenant of Down on October 17 (a new office replacing the Governor of Down), and finally a Knight of the Order of St Patrick on November 24, 1831. He receives an honorary LL.D. from the University of Cambridge on July 6, 1835.

Hill is a very strong supporter of the Irish language, and is president of the Ulster Gaelic Society (est. 1830). In this capacity he plays an important role in helping preserve records of the language, poetry, folk and song collections and much else.

Hill is disliked by Elizabeth Smith, diarist at Baltyboys House, County Wicklow, who feels snubbed by him when she and her husband first move into the area. Writing of him after his death she recalls “The late Lord never called upon me when I first came here although the Colonel waited upon him. The Colonel never went near him again.”

High-minded, if also at times high-handed in manner and self-important, Hill works hard himself and expects all his employees and tenants to be equally conscientious. Naturally, he is often disappointed. He is particularly concerned about his failure, despite all efforts and exhortations, to make his southern estates as efficient and well behaved as those in the north. Though an absentee owner in the south, he visits both Blessington and Edenderry regularly. It is during one of these periodic tours of inspection that he drops dead at Blessington on September 12, 1845. He is buried in St. Malachy Parish Churchyard at Royal Hillsborough, County Down. The funeral attracts an enormous crowd of mourners and is reported at some length in The Illustrated London News. His memory is perpetuated in an impressive pillar monument, with his statue on top, erected at Hillsborough in 1848.