The Christian holiday of All Hallows' Eve, celebrated on the same date, was originally celebrated on May 13, and was moved to its present date by Gregory III in the eighth century.

CNN: Happy Halloween

Syria's Patriarch Gregory III Laham of Antioch, who heads the Melkite Greek Catholic Church, on Thursday invited Francis to visit Syria, Jerusalem and Lebanon for peace and reconciliation, according to Syria's official news agency.

CNN: The new pope's first day: Mass with the cardinals

Ahlers and Gregory Clary and journalist Martin Rand III contributed to this report.

CNN: Panda cub dies at Smithsonian's National Zoo

With Gregory Sierra, Charles Martin Smith, Clarence Williams III, Sidney Lassick, and Robert Guenveur Smith.

NEWYORKER: Deep Cover

Pope Gregory VII may have humiliated the Emperor Henry IV, as Innocent III later humiliated Philip Augustus of France and King John of England.

ECONOMIST: Medieval history