This was the start of the long list of popes named Leo, Gregory and Benedict, said Melloni.

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John XXIII got away with it because he said it was in deference to his parish saint, John the Baptist, Melloni said.

CNN: What's in a name? Clues to be found in next pope's moniker

"In a church so hit by financial scandals, someone who has lived a life of poverty and rigor lays a good foundation for the papacy, " said Mr. Melloni.

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