Katia and Maurice Krafft were both born in the 1940s in the Rhine valley, close to the Miocene Kaiser volcano, though they didn’t know each other as children. They met on a park bench when they were students at the University of Strasbourg, and from that moment on, according to their joint obituary in the Bulletin of Volcanology, ‘volcanic eruptions became the common passion to which everything else in their life seemed subordinate’.