Thomas Grey , 1st Marquess of Dorset Thomas Grey , 7th Baron Ferrers of Groby , 1st Earl of Huntingdon , and 1st Marquess of Dorset , KG ( 1453 – 20 September 1501 ) , was an English nobleman , courtier and the eldest son of Elizabeth Woodville and her first husband Sir John Grey of Groby . Her second marriage to King Edward IV made her queen consort of England , thus elevating Grey ' s status at court and in the realm as the stepson of the King . Through his mother ' s assiduous endeavours , he made two materially advantageous marriages to wealthy heiresses - his first wife being Anne Holland ( daughter of the King ' s sister , Anne of York , Duchess of Exeter ) , and his second wife , Cecily Bonville , 7th Baroness Harington . By the latter he had 14 children . Family . Thomas Grey was born in 1453 at Groby Old Hall in the village of Groby , Leicestershire , as the elder son of Sir John Grey and his wife Elizabeth Woodville , who later became queen consort to Edward IV of England . His younger full brother , Sir Richard Grey ( 1457 - 1483 ) , was arrested by Richard , Duke of Gloucester on 30 April 1483 , after being accused of plotting to take the throne . Gloucester ' s forces later executed Richard Grey at Pontefract Castle . The Grey brothers had ten half - siblings by their mother ' s marriage to Edward IV . Career . His mother endeavoured to improve his estates by the conventional methods of their class and time , through his marriages and purchase of wardships . On the death of his stepfather , Edward IV , and his 12 - year - old half - brother , Edward V ' s , accession to the throne on 9 April 1483 , Grey proved unable to maintain his family ' s position . It was not possible to arrange a Yorkist regency . Internal fighting , particularly the long established battle for ascendancy in Leicestershire between the Grey and Hastings families , now on the national stage , allowed Gloucester to seize power and usurp the throne . On 25 June 1483 , an assembly of Parliament declared Richard III to be the legitimate king , and Thomas ' uncle and brother , Anthony Woodville , 2nd Earl Rivers and Richard Grey respectively , were executed . Later in the summer , learning of the apparent murder of both his young half - brothers , Grey joined the Duke of Buckingham ' s rebellion against Richard III . When the rebellion failed he fled to Brittany to join Henry Tudor , the future Henry VII , who pledged to marry Grey ' s half - sister Elizabeth of York and heal the Yorkist / Lancastrian division . However , just before Henry and the Lancastrian army left to launch their ultimately successful invasion of England in August 1485 , Grey heard rumours from England that his mother had come to terms with Richard III , and he was persuaded to desert Henry Tudor . He was intercepted at Compiègne on his way to England and played no part in the invasion or subsequent overthrow of Richard III . Grey was instead confined to Paris , as security for the repayment of a loan made to Henry Tudor by the French government , unable to return home until Henry VII was safely installed as king of England . Thereafter Henry VII took good care to keep his Queen ' s half - brother under control and Grey was not permitted to recover his former influence . Thomas Grey was confined in the Tower in 1487 during Lambert Simnel ' s rising and not released until after the House of Tudor victory in the Battle of Stoke Field . Though he accompanied the King on his expedition to France in 1492 , he was obliged to commit himself in writing to ensure he did not commit treason . He was permitted to assist in suppression of the Cornish rising in 1497 . Thomas Grey , Marquess of Dorset , died in London on 20 September 1501 , aged about 48 , and was buried in the collegiate church of Astley , Warwickshire . His wife survived him and married Grey ' s cousin , Henry Stafford , later Earl of Wiltshire . Marriages and issue . His mother sought to make provision for him by marriage to wealthy heiresses . He married firstly , at Greenwich in October 1466 , Lady Anne Holland ( c . 1455 - c . 1474 ) , the only daughter of Henry Holland , 3rd Duke of Exeter , and Anne of York . His mother - in - law was the second child and eldest surviving daughter of Richard Plantagenet , 3rd Duke of York , and Cecily Neville , thus sister to his mother ' s second husband King Edward IV . After Anne Holland died young without issue , Thomas married secondly , by papal dispensation 5 September 1474 , Cecily Bonville , 7th Baroness Harington of Aldingham and 2nd Baroness Bonville , the wealthiest heiress in England . Cecily Bonville , born in 1461 , was the daughter and heiress of William Bonville , 6th Baron Harington , by his wife Katherine Neville , daughter of Richard Neville , 5th Earl of Salisbury . Katherine was sister to the late Earl of Warwick and thus aunt to his daughters . By his second wife Grey had seven sons and seven daughters : Depictions in fiction . Thomas Grey , 1st Marquess of Dorset , is depicted in Shakespeare ’ s " Richard III " .