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 and invaded England. Elizabeth asked Paulet, Mary's final custodian, if he would contrive a clandestine way to "shorten the life" of Mary, which he refused to do on the grounds that he would not make "a shipwreck of my conscience, or leave so great a blot on my poor posterity". On 1 February 1587, Elizabeth signed the death warrant, and entrusted it to William Davison, a privy councillor. On 3 February, ten members of the Privy Council of England, having been summoned by Cecil without Elizabeth's knowledge, decided to carry out the sentence at once. At Fotheringhay on the evening