The Popes: A History, By John Julius Norwich

Who would imagine that such a scintillating book hides behind the austere title? Every page teems with startling detail about the bizarre lineage of 280 popes.

According to a contemporary, the Borgia Pope Alexander VI attracted women "like iron to a magnet". The early Pope Formosus was dug up after death and tried for perjury. Found guilty, the body was thrown in the Tiber.

In his first two years, the current Pope "managed seriously to offend... first the Muslims, then the Jews and finally the Protestant churches".

Sadly, the "mildly grotesque story" of Pope Joan is rejected on grounds of "sheer improbability" though there remains a "chaise percée" in the Vatican "admirably designed for a diaconal grope" to establish the sex of putative popes.