In the 19th century , the county continued to function in the part of Poland that had been incorporated into the Russian Empire ( `` Congress Poland '' ) , and as the Polish equivalent of the German `` Kreis '' in the German-governed Grand Duchy of PoznaÅ . In the 19th century , the powiats continued to function in the part of Poland that had been incorporated into the Russian Empire ( `` Congress Poland '' ) and , as the Polish equivalent of the German `` Kreis '' in the German-governed Grand Duchy of PoznaÅ .