Language became the basis of nation-building in Central Europe at the turn of the nineteenth and twentieth centuries. During the same period Czech, German and Polish nationalists had contested Upper Silesia as a multilingual region before the nation-states of Czechoslovakia, Germany and Poland took over this role. In the first half of the twentieth century, this land was divided and redivided among these nation-states. Each change entailed an alteration in language policies aimed at ennationalising Upper Silesia's inhabitants into one nation or another. Standard national language being the yardstick of nationality, the local non-standard language forms were earmarked for eradication because they could spur further emergence of Upper Silesia's ethnic groups or serve as a springboard for new nationalism(s). The Central European strain of ethnic nationalism steeped in language clashed with other loci of identity such as religion, the monarch or state. Sometimes this helped ethnic groups to survive despite ennationalising pressure exerted by the established nation-states. Officially, during the communist period, Warsaw managed to homogenise Upper Silesia into an indistinguishable part of the Polish nation-states. After 1989 it proved an illusion, as Upper Silesia seems to be the most ethnically and nationally diversified region in post-communist Poland.