In or before 1580 [his father] Oliver St John 3rd Baron St John (age 40) and [his mother] Dorothy Reid Baroness St John Bletso were married. She by marriage Baroness St John of Bletso.

In Apr 1602 Oliver St John 1st Earl Bolingbroke (age 22) and Elizabeth Paulet Countess Bolingbroke were married.

In 1623 [his son] Oliver St John 5th Baron St John (age 20) and [his daughter-in-law] Arabella Egerton Baroness St John Bletso were married. She the daughter of John Egerton 1st Earl Bridgewater (age 44) and Frances Stanley Countess Bridgewater (age 40). He the son of Oliver St John 1st Earl Bolingbroke (age 43) and Elizabeth Paulet Countess Bolingbroke. She a great x 4 granddaughter of King Henry VII of England and Ireland.

On 09 May 1628 [his son-in-law] John Carey 2nd Earl Dover (age 20) and [his daughter] Dorothy St John were married. She died eight weeks later. She the daughter of Oliver St John 1st Earl Bolingbroke (age 48) and Elizabeth Paulet Countess Bolingbroke. He the son of Henry Carey 1st Earl Dover (age 48) and Judith Pelham Countess Dover (age 37).

[his son] Anthony St John and Ann Keynshan were married. He the son of Oliver St John 1st Earl Bolingbroke and Elizabeth Paulet Countess Bolingbroke.

[his son] Paulet St John and Elizabeth Vaughan were married. He the son of Oliver St John 1st Earl Bolingbroke and Elizabeth Paulet Countess Bolingbroke.