William FitzWilliam (Lord Deputy) William FitzWilliam (Lord Deputy) Sir William FitzWilliam (1526–1599) was an English Lord Justice of Ireland and afterwards Lord Deputy of Ireland. In 1587, as Governor of Fotheringhay Castle, he supervised the execution of the death sentence on Mary, Queen of Scots. He was the Member of Parliament for Peterborough and represented County Carlow in the Irish House of Commons. He lived at Gainspark, Essex, and Milton Hall. FitzWilliam was born at Milton Hall, Northamptonshire, the eldest son of Sir William (d. 1576) and grandson of William Fitzwilliam, Sheriff of London, who had been treasurer and chamberlain to Cardinal Wolsey and
Mary, Queen of Scots through a woman, and would be lost from his family through a woman. This legendary statement came true much later—not through Mary, but through her descendant Queen Anne. Mary was baptised at the nearby Church of St Michael shortly after she was born. Rumours spread that she was weak and frail, but an English diplomat, Ralph Sadler, saw the infant at Linlithgow Palace in March 1543, unwrapped by her nurse, and wrote, "it is as goodly a child as I have seen of her age, and as like to live." As Mary was an infant when she inherited the throne,