Henry Benedict Thomas Edward Maria Clement Francis Xavier Stuart, Cardinal Duke of York was a Roman Catholic cardinal, and was the fourth and final Jacobite heir to publicly claim the thrones of Great Britain and Ireland, as the younger grandson of King James II of England. One of the longest-serving cardinals in history, Henry spent his whole life in the Papal States and became the Dean of the College of Cardinals and Cardinal-Bishop of Ostia and Velletri. Unlike his father James Francis Edward Stuart and elder brother Charles Edward Stuart, Henry made no effort to seize the thrones. After Charles's death in 1788, Henry became known by Jacobites as Henry IX and I, but the Papacy did not recognise Henry as the lawful ruler of Great Britain and Ireland and instead referred to him as the "Cardinal Duke of York". He was most widely known as the Duke of York, a title in the Jacobite peerage granted to him by his father.

The Roman Catholic Suburbicarian Diocese of Ostia is an ecclesiastical territory located within the Metropolitan City of Rome in Italy. It is one of the seven suburbicarian dioceses. The incumbent Bishop is cardinal Giovanni Battista Re. Since 1150, its bishop has been the Dean of the College of Cardinals. Its Cathedral is Basilica di Sant'Aurea.