After 1625 [his father] John Robartes 1st Earl Radnor (age 19) and [his mother] Letitia Isabella Smythe Countess Radnor were married. She by marriage Baroness Robartes of Truro in Cornwall. The difference in their ages was 24 years.

Before 07 Feb 1634 [his father] John Robartes 1st Earl Radnor (age 28) and Lucy Rich Baroness Robartes (age 19) were married. She the daughter of Robert Rich 2nd Earl Warwick (age 46) and Frances Hatton Countess Warwick.

Around 1666 [his future brother-in-law] John Pole 3rd Baronet (age 16) and Anne Morice Lady Pole (age 13) were married.

On 21 Oct 1674 Coplestone Bamfylde 2nd Baronet (age 36) and [his future sister-in-law] Jane Pole Lady Coplestone (age 20) were married at Houghton, Devon. She by marriage Lady Bampfylde of Poltimore in Devon.

Before 02 Jul 1680 Francis Robartes (age 30) and Penelope Pole were married. He the son of John Robartes 1st Earl Radnor (age 74) and Letitia Isabella Smythe Countess Radnor (age 50).

After 17 Jul 1685 [his step-father] Charles Cheyne 1st Viscount Newhaven (age 59) and [his mother] Letitia Isabella Smythe Countess Radnor (age 55) were married. She by marriage Viscountess Newhaven.

Before 03 Feb 1718 Francis Robartes (age 68) and Anne Fitzgerald were married. She the daughter of Wentworth Fitzgerald 17th Earl of Kildare and Elizabeth Holles Countess Kildare. He the son of John Robartes 1st Earl Radnor and Letitia Isabella Smythe Countess Radnor.