Mervyn Bragg's "In Our Time" series regularly enlightens and entertains substantial audiences on BBC Radio 4. Here are several episodes which reflect the diversity of this excellent radio programmes:
Dante's Inferno
The Dissolution of the Monasteries
The Spanish Armada
The Norman Yoke
The Peasants' Revolt
Social Darwinism
The Inca
The Song of Roland
The Emancipation of the Serfs
William and Caroline Herschel
The Rosetta Stone
Doggerland
Islamic Law and its Origins
Sunni and Shia Islam
Frankenstein
And there are so many more! Simply search for them on YouTube.