I read somewhere a deal was made in 2005 and Benedict was made Pope and would reign till 2013,then resigning to Pope Francis. At the time Ratzinger was the same age as Bergolio was in 2013 at the start of his Papacy. Pope Francis in 2021 will have reigned 8 years.
"After having repeatedly examined my conscience before God, I have come to the certainty that my strengths, due to an advanced age, are no longer suited to an adequate exercise of the Petrine ministry... In today's world, subject to so many rapid changes and shaken by questions of deep relevance for the life of faith, in order to govern the barque of Saint Peter and proclaim the Gospel, both strength of mind and body are necessary, strength which in the last few months, has deteriorated in me to the extent that I have had to recognise my incapacity to adequately fulfil the ministry entrusted to me." Pope Benedict XVI
"Well, it turns out the emeritus pope is doing just fine, thank you. Yes, he is nearly 87, slightly stooped and walking with a cane. But his overall health is pretty good and his spirits — and his wit, say friends who see him — are as strong as ever.
“His memory is fresh and his eyes are very bright and joyous,” the Rev. Stephan Otto Horn, head of a close-knit circle of Benedict’s former theology students, said after meeting Benedict in June.
Indeed, Benedict receives a regular stream of visitors in a retrofitted Vatican monastery where he passes the days praying but also reading, playing the piano, and corresponding with old friends and intellectual foes, like the Swiss theologian Hans Kung."
“We are all seeing the impact of Pope Francis on the world, not only on the faithful in the church, but on the world; it is a huge impact, and this impact was also facilitated by Pope Benedict in his resignation,” Archbishop Georg Gaenswein, Benedict’s closest aide and a leading promoter of his boss’ legacy, said this month. “He opened up a possibility that until then was not there.”
In this view, Francis is really building Benedict’s church, as one commentator wrote, and Benedict in fact deserved Time magazine’s “Person of the Year” every bit as much as Francis, said another.
So what does Benedict himself make of all the maneuvering?
He is probably rather amused. Those who know him say that his penchant for sarcasm is as sharp as ever, and if he doesn’t agree with everything Francis is doing — Gaenswein himself admitted to some exasperation with the new pope’s populist ways — Benedict has told friends that “theologically he is very much in the same line with Pope Francis.”
http://www.religionnews.com/2014/02/25/analysis-surprising-afterlife-pope-benedict-xvi/