Answer
+KAROLUS DEI GRA DUX BURG, CO F is a Latin phrase meaning "Charles, by the grace of God, Duke of Burgundy, Count of Flanders". It was the legend on the Double Briquet, a gold coin issued by Charles the Bold, Duke of Burgundy, in 1475. The coin is notable for its large size and intricate design, and is considered to be one of the finest examples of medieval coinage.