Leslie Stephen,
Dictionary of National Biography…
(1897)
“ John, third baron St. John of Bletsho, by his wife Dorothy, daughter and heiress of Sir John Rede of Odington, Gloucestershire. The St. Johns of Bletsho and the St. Johns of Lydiard-Tregoz [see St. John, Oliver, Viscount Grandison] were both descended from Sir Oliver St. John, K.B. (d. 1437) , and his wife Margaret Beauchamp, who afterwards married John Beaufort, second duke of Somerset, and was grandmother of Henry VII. The Bletsho family was the elder branch (see pedigree in G.E.C.'s Peerage, s.v. 'Bolingbroke') . Sir Oliver's great-great-grandson, Oliver, was created first baron St. ”
