Henry Grey was created Duke of Suffolk jure uxoris on 11 October 1551, in the same ceremony that elevated John Dudley to the Dukedom of Northumberland. Protestantism Henry Grey was best known for his zeal for the Protestant faith. The Swiss reformer Heinrich Bullinger dedicated a book to him in 1551 and frequently corresponded with the family. In Parliament and on the Privy Council, Grey pushed for further Protestant reforms. He is credited with making Leicestershire one of the most reliably Protestant counties in early modern England. Queen Jane Seriously ill, and fearing his own death, King Edward VI granted Northumberland's request for the marriage of Suffolk's daughter Lady Jane Grey to Northumberland's son, Lord Guildford Dudley, on 25 May 1553. Edward later altered his will to make Jane his designated successor. Edward died on 6 July 1553, and three days later Suffolk, Northumberland, and other members of the Privy Council proclaimed Jane queen. This proclamation failed; not by a large-scale rallying of forces in the country to Henry VIII's eldest daughter, the future Queen Mary I, as is often thought, but by a wavering Privy Council switching its allegiance to Mary during Northumberland's absence on the campaign against her. The decision was led by Henry Fitzalan, 12th Earl of Arundel, and William Herbert, 1st Earl of Pembroke. Arundel had been imprisoned earlier by Northumberland for having sided with the previous Protector, Somerset; but it is not clear why Pembroke revolted, especially since his son and heir, Henry Herbert, married Henry Grey's other daughter, Katherine, the same day as Jane's wedding. The country was divided in its loyalties to the two contenders for queen at the time. By his wife's friendship with the new Queen Mary, Grey and his daughter and son-in-law temporarily avoided execution. However, Mary had Henry Grey beheaded on 23 February 1554, after his conviction for high treason for his part in Sir Thomas Wyatt's attempt (JanuaryFebruary 1554) to overthrow her after she announced her intention to marry King Philip II of Spain. Mummified head According to Walter George Bell (writing in 1920), in 1851 the severed head of the Duke of Suffolk was discovered in a vault in the Church of Holy Trinity, Minories, in the City of London, suggested to have been preserved by the tannin-rich oak sawdust used to pad the basket on the scaffold on which he had been beheaded 297 years earlier.