Rare sight of two Popes together

This is the first time in more than 600 years that two popes will be alive at the same time and in each others company. Usually one would have to die before the other takes over...but Pope Benedict XVI retired last month.
Pope Francis flew to Castel Gandolfo by helicopter today to visit Benedict who has been living at the papal villa since he officially retired on February 28. They prayed together in the chapel before sharing a private lunch.