The history of Germans in Poland dates back almost a millennium.Poland was at one point Europe's most multiethnic state during the medieval period. Its territory covered an immense plain with no natural boundaries, with a thinly scattered population of many ethnic groups, including the Poles themselves, Germans in the cities of West Prussia, and Ruthenians in Lithuania. 5 to 10% of immigrants were German settlers. (In the Middle Ages, there was no homogeneous German state; the label "German" generally refers to German-speaking people, including Germanized Polabian Slavs and Lusatian Sorbs.)