Wikipedia
Mainkreis (Bavaria)
The Mainkreis (German: Main District) was one of the 15 administrative districts (German: Regierungsbezirke) of the Kingdom of Bavaria between 1806 and 1837 (after 1817 Obermainkreis) named after its main river Main. It was the predecessor of the Regierungsbezirk Oberfranken (Administrative Regional District of Upper Franconia).