Poznań is Posen - a former German area with lot of German literature culture
It was majority Polish during that period, with Germans making up at most 40% of the population, or ~65000, when it became a part of Poland again.
https://upload.wikimedia.org/wikipedia/commons/b/bb/Roman_Em...
Why would anyone make that argument? Claiming Poznań as German reeks of irredentism. Germanic != German. Do germans still claim the cities of other Germanic countries and former lands like Austria, Czechia, Denmark, Norway, Belgium, Netherlands, Luxembourg and the Baltics as German?
> Former German area.
Former from 1939 to 1945.