Ernestine Wettin duchy formed in the 1826 redistribution of the Saxon lands, uniting the geographically separate duchies of Coburg and Gotha; its dynasty supplied consorts and kings to Britain, Belgium, Portugal and Bulgaria.
Duke Charles Edward was forced to abdicate and the duchy was proclaimed a republic in November 1918; Gotha joined the new State of Thuringia in 1920 while Coburg voted to join Bavaria.
Biography of the duchy's last reigning duke, covering its 1918 end; polity-specific, verified on Open Library (ISBN 9781527513402).