What was wrong with Jorge? Cardinal Jorge Mario Bergoglio not only became Pope today, he became Francis I, likely after St. Francis of Assisi, the first celebrity anti-poverty activist of the early modern world. Why the name change? While there doesn’t appear to be a written rule barring Popes from using their real names, it’s been de facto Papal law since the mid-16th century to switch. Currently, it’s the very first question the new Pope is asked after being elected, while still ensconced in the Sistine Chapel.
The last Pope to use his official name was Marcello Cervini degli Spannochi, who became Marcellus II. The practice of name-switching appears to have started in 533, when a Pope with a pagan name–Mercurius–was elected. Having deemed that unsuitable for obvious reasons, he switched to John II. Between his and Marcellus’s reign, some Popes kept their given names, and some didn’t. You’ll notice from the “I” following his name that Bergoglio has become the first Francis ever. The last time a Pope chose a virgin name was in 913, when Landus became Pope Lando I. Though that seems like cheating.
Update: As a reader points out, John Paul I also gave himself a new moniker in 1978. Though both John and Paul, of course, had been chosen previously. John Paul II, who succeeded him, chose the name to honor his predecessor, who died after only 33 days in the Vatican.