Lady Mary Keyes (née Grey; 20 April 1545 – 20 April 1578) was the youngest daughter of Henry Grey, 1st Duke of Suffolk, and Frances Brandon, and through her mother had a claim on the crown of England. Early life Mary Grey, born about 20 April 1545, was the third and youngest daughter of Henry Grey, 1st Duke of Suffolk, and Lady Frances Brandon, daughter of Charles Brandon, 1st Duke of Suffolk, and Mary Tudor, the younger of the two daughters of King Henry VII and Elizabeth of York. Mary had two sisters, Lady Jane Grey and Lady Katherine Grey. Throne claims As great-grandchildren of Henry VII, Mary and her sisters were potential heirs to the crown. When King Edward VI died on 6 July 1553, he left a Will (approved by John Dudley, 1st Duke of Northumberland) naming Mary's eldest sister, Jane, recently married to Northumberland's son Guildford Dudley, to succeed to the throne. Some weeks before, on 25 May 1553, Mary Grey, still a young child, had been betrothed to her distant cousin Arthur Grey, 14th Baron Grey de Wilton, whose father was an ally of Northumberland. The attempt to secure a Protestant succession failed, and although King Edward was briefly succeeded by Jane Grey, the Privy Council of England changed sides and proclaimed his half sister, Mary. Northumberland was executed on 22 August 1553. Queen Mary spared Jane's life and the lives of Jane's husband and father, but after the suppression of the Wyatt rebellion in early 1554, all three were executed, Jane and her husband on 12 February 1554, and Jane's father shortly thereafter, on 23 February. After Queen Mary's accession Mary Grey's betrothal to Arthur Grey was dissolved. On 1 March 1555, Mary's mother, Frances Brandon, took a second husband, Adrian Stokes. When Frances died on November 20, 1559, she left a life estate in most of her property to Stokes, while Mary received only a small inheritance yielding a modest income of £20 a year. However, Queen Elizabeth, who had acceded to the throne in November 1558, appointed Mary Grey as one of her Maids of Honour and granted her a pension of £80. Since Queen Elizabeth was childless, the two surviving Grey sisters were next in the line of succession under King Henry VIII's will, and were not permitted to marry without the Queen's permission. In December 1560, however, Katherine Grey secretly married