Cardinal Peter Erdo, of Hungary, celebrates a mass in St. Balbina basilica in Rome, Sunday March 10, 2013. Cardinals from around the world gather this week in a conclave to elect a new pope following the stunning resignation of Benedict XVI. In the secretive world of the Vatican, there is no way to know who is in the running, and history has yielded plenty of surprises. Yet several names have come up time repeatedly as strong contenders for the job. Erdo, the Archbishop of Esztergom-Budapest, is among those considered to have a credible shot at the papacy. (AP Photo/Alessandra Tarantino)