Hertford, Katherine Seymour, Countess of, 1540-1568

found: Morgan, T. Allegations in behalf of the high and mighty princess, the Lady Mary, now Queen of Scots, against the opinions and books set forth in the part and favour of the Lady Katherine, and the rest of the issues of the french Queen, touching the succession of the crown, 1690.

found: Cokayne, G. Complete peerage, 1910:vol. 6, p. 505 (Sir Edward Seymour cr. Earl of Hertford 1559, m. Katherine, the repudiated wife of Henry Herbert (note d: her marriage was on the same day (21 May 1553) as that of Lady Jane; it was dissolved or declared null by the influence of the Earl of Pembroke, her husband's father, when the Grey family had fallen); the Countess b. 1540, d. 1567/8)

found: Cokayne, G. Complete peerage, 1910:vol. 4, p. 421 (Henry Grey, cr. Duke of Suffolk 1551; note c states (The sole heirship ... would seem to vest in the heirs of Katherine Grey, the Duke's 2nd da., who m. Edward (Seymour), Earl of Hertford))

found: DNB:vol. 6, p. 105 (Dudley, Lady Jane, 1537-1554, Lady Jane's sister Catherine married Lord Herbert, the Earl of Pembroke's son)