In 1656 Walter St John 3rd Baronet (age 33) was elected MP Wiltshire.

In 1659 Walter St John 3rd Baronet (age 36) was elected MP Wiltshire.

In 1661 Walter St John 3rd Baronet (age 38) was elected MP Wootton Bassett.

Evelyn's Diary. 20 Oct 1664. Hence, to see the famous wells, natural and artificial grots and fountains, called Bushell's Wells, at Enstone. This Bushell had been Secretary to my Lord Verulam. It is an extraordinary solitude. There he had two mummies; a grot where he lay in a hammock, like an Indian. Hence, we went to Dichley [Map], an ancient seat of the Lees, now Sir Henry Lee's (age 25); it is a low ancient timber-house, with a pretty bowling-green. My Lady gave us an extraordinary dinner. This gentleman's [his sister] mother (age 49) was Countess of Rochester, who was also there, and Sir Walter St. John (age 42). There were some pictures of their ancestors, not ill painted; the great-grandfather had been Knight of the Garter [Note. Reference to Henry Lee of Ditchley who was not great-grandfather; he was second-cousin once-removed]; there was a picture of a Pope, and our Savior's head. So we returned to Cornbury.

In Oct 1679 Walter St John 3rd Baronet (age 57) was elected MP Wiltshire.

In 1681 Walter St John 3rd Baronet (age 58) was elected MP Wiltshire.

Evelyn's Diary. 20 Dec 1684. A villainous murder was perpetrated by [his son] Mr. St. John (age 32), eldest son to S' Walter St. John (age 62), a worthy gentleman, on a knight of quality [Sir William Estcourt], in a tavern. The offender was sentenc'd and repriev'd. So many horrid murders and duels were committed about this time as were never before heard of in England, which gave much cause of complaint and murmurings.

Note. Following the aquittal of Edward Nosworthy the jury repaired to the Globe tavern in Fleet Street. An altercation broke out between St John and Francis Stonehouse. St. John and Edmund Webb both ran Estcourt through with their swords. Both were found guilty of murder, and condemned to death. St. John's mother [[his wife] Johanna St John Baroness St John Lydiard Tregoze (age 53)] obtained a pardon for him at the reported price of £16,000. St. John was expected to go abroad for some time, but publicly entered the next parliamentary election at Wootton Bassett a few weeks after the close of his case, and was duly elected to James II’s first Parliament.

In 1690 Walter St John 3rd Baronet (age 67) was elected MP Wiltshire.

Before 1708 Godfrey Kneller (age 61). Portrait of Walter St John 3rd Baronet (age 85).

Before 03 Jul 1708. Michael Dahl (age 49). Portrait of Walter St John 3rd Baronet (age 86). Lydiard House.