A reigning pope and ex-pope faced each other for the first time in at least 600 years when Pope Francis travelled south of Rome to meet his predecessor, "pope emeritus Benedict XVI".
Vatican magistrates formally charged Pope Benedict's butler with illegal possession of secret documents and said a wider investigation would take place to see if he had any accomplices who helped him leak them.
Pope Benedict, speaking before a larger than usual crowd at his penultimate Sunday address, asked the faithful to pray for him and for the next pope.
Next Saturday Francis will visit and have lunch with Benedict XVI in a historic meeting that will bring together the first pope to resign in 600 years and the first non-European pope in modern times and first Latin American head of the Roman Catholic Church in history.
Pope Benedict and Cuban President Raúl Castro met on Tuesday for talks on a papal trip that has sparked hopes for economic and political change, but one national leader said there would be no political reform on the communist island.
Pope Benedict marks two milestones this week and while his health appears stable, signs of frailty have again prompted speculation over whether he will be the first pontiff in seven centuries to resign.
Pope Benedict's butler was arrested in connection with an investigation into leaks of confidential documents, some alleging cronyism and corruption in Vatican contracts, a senior Vatican source said.
Pope Benedict condemned violence in God's name, but said that 10 years after the Sept. 11 attacks, the world still had much to do to address the grievances that can give rise to acts of terrorism.
Pope Benedict said on the developed world could not continue to look down on Africa "with the judgmental tone of a moralizer" and impose rules, but must come up with real partnership solutions to solve the continent's many problems.
Pope Benedict, putting his mark on his Church's future, on Saturday inducted 22 men into the exclusive group of cardinals who will one day elect one of their own to succeed him as leader of the world's 1.3 billion Roman Catholics.
Pope Benedict urged Cubans to build a better, "renewed and open society" and pressed the communist government to give the Catholic Church more liberties to help the country as it faced an uncertain future.