Mary's life was not as exciting as her sisters, Jane and Katherine Grey. But after their death she was the last surviving grandchild of Mary Tudor, and therefore some people thought she might be heiress to the English throne. She married the royal gatekeeper Thomas Keyes in 1565 but this was without Queen Elizabeth's permission. But like her sister Katherine's marriage to Edward Seymour, Earl of Hertford, Queen Elizabeth was angry. Elizabeth claimed that she wanted "no bastard Keyes". Elizabeth put Mary under house arrest. She was released after the death of her husband in 1572 and was permitted to attend Court occasionally.