Reflection on the process of defining and redefining the notion of Polishness after 1918, and thus, an attempt to answer the questions: ‘What is Polishness?’; ‘Is it possible to talk about its single, monolithic, well-defined form in relation to a specific point in history as well as at present?’ – were the main topics of an international conference organised by the Centre for Historical Research on 21st–22nd June 2018 and held at the glamourous Louise-Schroeder-Saal of the Rotes Rathaus (Red Town Hall) in Berlin. Held on the occasion of the centenary of Poland’s regained independence, the event was simultaneously a festive farewell to Professor Robert Traba, the founder and Director of the Berlin-based Centre for Historical Research, Polish Academy of Sciences. The attendees included researchers from Poland as well as scholars from Germany and France, representing various fields of science: history, literature, sociology, political science, law, Slavic studies, Polish studies, and art history. A total of twenty-seven papers and comments, in Polish and/or German, were submitted. The conference ended with a panel discussion (lasting over two hours) on ‘Individual identities in the face of collective ideas of Polishness’ (now available on the CHR website: http://www.cbh.pan.pl/de/fotobericht-und-film-zur-konferenz-derunvollendete-krieg).