Margaret was the eldest surviving child of George, Duke of Clarence and Isabel Neville. Her mother died when she was three years old, and her father was executed for treason two years later, leaving Margaret and her brother Edward in the care of her aunt, Anne Neville, After the deaths of Anne and her uncle, Richard III, Margaret became one of the last Plantagenet survivors of the Wars of the Roses. The new king, Henry VII, married her to his cousin Richard Pole to neutralize her as a potential political threat. (Her brother Edward was eventually executed in 1499.) She later served Katherine of Aragon during her brief tenure as Princess of Wales.
Margaret had five children by Richard. His death in 1504, however, left her nearly destitute. When Henry VIII took the throne, however, Margaret again became the now-Queen Katherine’s lady-in-waiting. Parliament restored her to the earldom of Salisbury and made her a countess. She became a wealthy patroness of Renaissance scholarship and, in 1520, she became Princess Mary’s governess.
By 1538, however, Margaret had fallen out of favor once again. She was a devout Catholic and had been a staunch and vocal supporter of Queen Katherine and Princess Mary. Despite her advanced age, her Plantagenet blood made the increasingly paranoid Henry VIII see her as a threat. She was stripped of her land and titles and imprisoned, along with her grandson Henry, in the Tower of London in 1539, where would spend the last two years of her life.
Margaret was finally sentenced to death in 1541, despite being by then a frail and elderly woman. Her execution was a grisly, botched affair. She was buried in the Tower chapel. In the nineteenth century, she was later beatified as a Catholic martyr by Pope Leo XIII.