News that Pope Francis, who is 85, has had to cancel an important visit to south Sudan, and the fact that he is usually now seen in public in a wheelchair, has inevitably excited the Roman gossip machine to speculate on his possible retirement. He was elected Pope in 2013 after his predecessor Benedict XVI resigned, though not primarily through ill health – more from spiritual exhaustion. Both of them were conscious of the final years of John Paul II, when sickness gradually loosened his grip on the administration of the papacy in a way that did not benefit the Church. Indeed some of the problems his successors had to deal with date back to that period.