PG Wodehouse fans - Bertie's parents...?

Are there any references in the Jeeves and Wooster books to what happened to Bertie’s mother and father?

I assume that they are dead - this is why Bertie spends his time with his Aunts? - and that this is why he has his substantial private income, but are there any more details than that?

Off the top of my head I can only recall one or perhaps two mentions of his immediate family but they don’t go into any great depth…

Thanks,
– Quirm

I can’t find any reference but, knowing Wodehouse’s style, I’m sure they died peacefully. Bertie’s been on his own for years, was an only child, and was raised primarily by his fearsome aunts.

There is a sister mentioned in one story, where Bertie thinks of adopting a daughter and is quickly dissuaded from this idea by visiting a girls’ school (The name of the story temporarily escapes me). The sister and her children live in India, I believe, and never actually make an appearance.

I have always wondered myself if Aunts Agatha and Dahlia are sisters–I assume so, but I can’t think of any point where this is established. And, if they are, are they Bertie’s father’s sisters, or his mother’s?