Forced to abdicate the Scottish throne, Mary Stuart, popularly known as Mary, Queen of Scots, fled across the border to England where she pleaded for political asylum from her cousin the Queen of England. Though distrustful of Mary, Elizabeth allowed her to remain in England. Mary’s presence created fresh trouble. 

Mary was both a strong Catholic and a strong claimant to the English throne. Her grandmother was Margaret Tudor, the sister of King Henry VIII. Since Elizabeth was unmarried without an heir, Mary was considered by many Catholics as being the rightful Queen of England. Sensing the threat Elizabeth ordered Mary’s arrest, keeping her in comfortable confinement for the next nineteen years of her life.