William Seymour (1588–1660), the husband of the unfortunate Lady Arabella Stuart, first Marquis and second Earl of Hertford and second Duke of Somerset, was received into the Church at St Omer in the late months of 1611. He was the second son of Lord Beauchamp, (1561–1612), who inherited the Suffolk claim to the throne through his mother, Catherine Grey, (1538–1568), the sister of Lady Jane Grey, who according to the will of their grandfather, Henry VIII stood next in the succession to Elizabeth.