President Jimmy Carter, who died earlier this week, has been praised for his humanitarian instincts. Not for nothing did he receive the Nobel Peace Prize in 2002, long after his presidency, for his continuing work in promoting human rights around the world. But as a Hungarian-born writer, my warm feelings towards him will always be associated with one of his lesser-known acts of international diplomacy: the return to Hungary of its most valued symbol of Hungarian nationhood, the Crown of St Stephen.