On 7 December 1970, fifty years ago this year, the Chancellor of the Federal Republic of Germany, Willy Brandt, visited the Warsaw Ghetto during an official visit to Poland. There, he lay a wreath of flowers in memory of the Jews murdered during the Second World War and, unpredictably, kneeled before the Monument to the Ghetto Heroes. Tragically stark, this picture, which associates political action with historical memory, became an iconic and ground-breaking image in photographic history, with a universal moral and political resonance. In 1971, Willy Brandt received the Nobel Peace Prize. In this Register section, the art historian Nicola Hille interprets the impact of this extraordinary precedent with great originality, questioning the relevance and validity in the present day of an act which at the time divided German public opinion.