Well known for his histories of Norman Sicily, Venice, the Byzantine Empire and the Mediterranean, John Julius Norwich has now turned his attention to the oldest continuing institution in the world, tracing the papal line down the centuries from St Peter himself - traditionally (though by no means historically) the first pope - to the present day.

Of the 280-odd holders of the supreme office, some have unquestionably been saints; others have wallowed in unspeakable iniquity.

Nepotistic, vain, pompous and idle - Pius VI was not an ideal choice as pope at any time and certainly not during the revolutionary tumult of the late eighteenth century. In today's episode of The Popes, John Julius Norwich explores one of the most dangerous times for the authority of the Vatican.

Producer: David Roper
A Heavy Entertainment production for BBC Radio 4. Show less