‘Berlin is a city condemned forever to become, never to be.’ Perhaps the most quoted sentence about the German capital, the art critic Karl Scheffler’s acerbic aperçu is as true today as it was when he coined it in 1910. John Kampfner uses it as an epigraph for the final chapter of In Search of Berlin, his tribute to a metropolis he sees as uniquely protean.

As I write, in the corner of my eye is a physical token of Berlin’s volatility. It is a substantial lump of concrete, kept under glass because of its asbestos content. It is not a thing of beauty, but a piece of history, for this fragment of the Berlin Wall was the very first chunk to be hacked off by a pickaxe-wielding resident in one of the streets bisected by the ‘Anti-Fascist Protection Barrier’ (its official name) in an impromptu evening ceremony, just a day after the Wall had opened. The man handed it to me, one of the watching journalists. I have kept it as a memento of the most momentous event of my life, one in which I was privileged to play a minor role as the Daily Telegraph’s Eastern Europe