1) Kingdom of Bavaria 
The Regenkreis, with Straubing and later Regensburg as its capital, existed between 1806 and 1837 as one of the 15 districts of the Kingdom of Bavaria. Its name meant in German the `District of the Regen” because the Regen River ran through it. It was the predecessor of the Regierungsbezirks Oberpfalz (Administrative Regional District of Upper.....