William Seymour, 2nd Duke of Somerset was the great-grandson of Edward Seymour, 1st Duke of Somerset (c.1500-1552), the uncle of King Edward VI and Lord Protector of England. Seymour made a secret marriage at Greenwich on 22 June 1610 to Arbella Stuart (d.1615), daughter of Charles Stuart, 1st Earl of Lennox and Elizabeth Cavendish. Arbella was thirteen years his senior, and King James I disapproved of the marriage as the union of two potential Tudor pretenders to the throne, who were respectively fourth and sixth in line, could only be seen as a threat to the ruling dynasty. As a result, William was condemned to life
Edward Seymour, 1st Duke of Somerset his attentions to Elizabeth by letter, planning to marry her. Elizabeth was receptive, but, like Edward, unready to agree to anything unless permitted by the Council. In January 1549, the Council had Thomas Seymour arrested on various charges, including embezzlement at the Bristol mint. King Edward himself testified about the pocket money. Most importantly, Thomas Seymour had sought to officially receive the governorship of King Edward, as no earlier Lord Protectors, unlike Somerset, had ever held both functions. Lack of clear evidence for treason ruled out a trial, so Seymour was condemned instead by an Act of Attainder and beheaded