Our Man in Roma

Secretive, hierarchical, traditionalist, with a penchant for discreet mortification of the flesh, and a history of supporting fascist and authoritarian regimes: Opus Dei. Founded in 1928 in Spain, Opus Dei and Pope Jean Paul II were very buddy buddy. Now, Opus Dei have a new guy in place: Cardinal Ratzinger, aka Benedict XVI.
Read The Da Vinci Code? Half the world and his wife have. I found it a rattlingly good page turner, but as stories go not half as good as Umberto Eco's 1988 Foucault's Pendulum. I don't know what Opus Dei think of Eco's book, but this is what they say about Brown's.
Listening yesterday to the CNN-ized BBC Worldservice, I learned that Popes have taken a nom de plume since the sixth century when someone called Mercury was elected. Since that name was the name of a Roman god and thus "pagan", Merc chose a culturally and spiritually more agreeable name: Benedict.
Which prompts the question: why has Ratzinger chosen Benedict? Well, it means: bless well. But why stop there? A look at the life of the previous Papal Benedict may offer further clues. Or not, as the case may be. So who was Benedict XV?