The late president, in Sudan in 2010, often went to places with refugees, poverty, disease and despair to see and bear witness like the Bible school teacher he was back home.

Were Putin to live until he was 100 he would doubtless still seek to cling to power. Jimmy Carter, who has died after reaching that great age, was president of the United States for just four years and lived on for 44 years after ending his one and only term in the White House.