His father
Note by Henry Craik to Letters 9 from Journal To Stella

Was Sir Henry St. John, a well-known man about town. He was the representative of a family which had become distinguished in the reign of Elizabeth. Curiously enough, he was created Viscount St. John, in 1716, after his famous son had not only won the same honour, as Viscount Bolingbroke, but had suffered attainder on the charge of treason.