III sent the children to Sheriff Hutton Castle in Yorkshire. In 1485, he was defeated and killed at the Battle of Bosworth by Henry Tudor, who succeeded him as Henry VII. The new king married Margaret's cousin, Elizabeth of York, Edward IV's daughter, and Margaret and her brother were taken into their care. Soon, young Edward, a potential York claimant to the throne, was moved to the Tower of London. Edward was briefly displayed in public at St Paul's Cathedral in 1487 in response to the presentation of the impostor Lambert Simnel as the "Earl of Warwick" to the Irish lords. Shortly thereafter, (probably in November 1487) Henry VII gave Margaret in marriage to his cousin, Sir Richard Pole, whose mother was a half-sister of the king's mother, Margaret Beaufort. When Perkin Warbeck impersonated Edward IV's presumed-dead son, Richard of Shrewsbury, 1st Duke of York, in 1499, Margaret's brother Edward was attainted and executed for involvement in the plot. Richard Pole held a variety of offices in Henry VII's government, the highest being Chamberlain for Arthur, Prince of Wales, Henry's elder son. When Arthur married Catherine of Aragon, Margaret became one of her ladies-in-waiting, but her entourage was dissolved when Arthur died in 1502 aged fifteen. When her husband died in 1505, Margaret became a widow with five children. She had a small estate of land, inherited from her husband, but no other income and no prospects. Henry VII paid for Richard's funeral. To ease the situation, Margaret devoted her third son, Reginald Pole, to the Church; he was to have an eventful career as a papal Legate and later as Archbishop of Canterbury. Later in life, he bitterly resented her abandonment of him. After her husband's death, Margaret had such inadequate means to support herself and her children that she was forced to live at Syon Abbey as the guest of the Bridgettine nuns. She remained there until she returned to favour when Henry VIII came to the throne in 1509. Countess of Salisbury Henry VIII married Catherine of Aragon in 1509 and Margaret was again appointed as one of her ladies-in-waiting. In 1512, an Act of Parliament restored to Margaret the Earldom of Salisbury and some of her brother's land which had belonged to it, for which she paid 5000 marks (£2666.13s.4d), . Henry VII had controlled them first while her brother was a minor and then during