[1] Ponsonby was the eldest son of Viscount Duncannon (who succeeded as the 2nd Earl of Bessborough in July 1758) and Lady Caroline Cavendish, daughter of the 3rd Duke of Devonshire.

[5] Tired of Duncannon's vacillating abusive temper, and craving for love in her life, Harriet started a disastrous affair with Richard Brinsley Sheridan.

[6] Perhaps chastened by time and age, by 1820 Duncannon rather miraculously ceased his abuse, and he and Harriet eventually settled into a companionable marriage.

On the other hand, he was a notoriously cruel husband, fluctuating between sweet or obsessive attentiveness, neglecting Harriet entirely, or physically abusing her.

Their fears were often proven, as when he threatened violence if Harriet did not hand over her marriage settlement to him after losing an especially ruinous gambling round.