As the world waits for the name of the new pope, predictions are flying about what moniker the next pontiff will adopt.

The leaders of the early church kept their birth names, but starting in 533 AD many heads of the church began taking new names after their election. The first pope to do so, Pope John II, gave up his baptismal name Mercurius because of its pagan roots.

That's not to say there have been no popes with pagan names. There was even a Pope Dionysius in the third century AD, although, to be fair, the name was very common during the period. Dionysus was the ancient Roman god of drunkenness and ecstatic ritual.

UPDATE: Cardinal Jorge Mario Bergoglio of Argentina was elected Pope on Wednesday and took the name Francis. He is the first Pope from the Americas.

Doubles names, such as John Paul, are a relatively new innovation. The first to take a double name was John Paul I in 1978.

A new pope can take any name he wishes, but tradition dictates that Peter is off limits. While a new pope isn't officially banned from using the name of the Catholic Church's first leader, only antipopes (those not officially recognized by the Vatican) have ever claimed Peter.

Generally, a new pope chooses a new based on a papacy he wishes to pay tribute to or imitate.

Check out the 10 most popular papal names in the slideshow below and share your predictions on what moniker the new pope will choose in the comments.

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  • 10. Urban (Tie)

    Eight popes total. Pope Urban VIII pictured.

  • 10. Boniface (Tie)

    Eight popes total (almost nine) as Pope Boniface VII was an <a href="http://en.wikipedia.org/wiki/Antipope">antipope</a>. Pope Boniface IX pictured.

  • 8. Stephen (Tie)

    Nine popes, or eight depending on your counting. The first Pope Stephen died before he could be made a bishop and so isn't on all the official papal lists. Pope Stephen IX pictured.

  • 7. Pius

    Twelve popes total. Pope Pius XII pictured.

  • 6. Leo

    Thirteen popes total. Pope Leo XIII pictured.

  • 5. Innocent

    Thirteen popes total. Pope Innocent XIII pictured.

  • 4. Clement

    Fourteen popes total. Pope Clement XIV pictured.

  • 3. Benedict

    Fifteen popes total (almost 16) as Pope Benedict X was an <a href="http://en.wikipedia.org/wiki/Antipope">antipope</a>. Pope Benedict XVI pictured.

  • 2. Gregory

    Sixteen popes total. Pope Gregory XVI pictured.

  • 1. John

    Twenty-one popes total. Pope John XXIII pictured.