Davies Gilbert,
The Parochial History of Cornwall
(1838)
“ He married Elizabeth Blount, by whom he had issue Edward Courtenay the 18th Earl of Devon (and last of the family of these Courtenays) that died at Padua, in Italy, without issue, 1556, 4th of October. Edward Courtenay of Haccomb, or Boconnoc, aforesaid 16th Earl of Devon, had four sisters, as is set down in his will, dated 1509, in the first year of the reign of King Henry VIII. which were thus disposed of in marriage, Elizabeth was married to John Trethyrfe of Trethyrfe, from whom Courtenay of that place, and Vyvyan of Trelowarren is descended ”
