Bump
I'd listen to this occasionally on the radio but never thought of looking for it as a podcast until now. Now I'm plowing through all ~700 episodes...
In Our Time - It's a ~45min show by BBC Radio 4 that's been going since 1998 where the host, Melvyn Bragg, and a panel of experts discuss a certain topic.
You can search the shows broadly by culture, history, religion, science or philosophy, or by a ton of different eras. I'd really recommend it for anyone who has an interest in general knowledge. Here's a wikipedia list of all the show -
List of In Our Time programmes