The double-helm is a medieval coin specific to the county of Flanders. Minted under Philip the Bold, Duke of Burgundy, it was produced exclusively at the mint in Ghent, under the supervision of master mintmaster Jehan Thomas. Its fineness, or fine metal content, is 979 per 1000. The monetary ordinances, documents specifying the types of coins to be issued, date from October 29, 1386, and October 1, 1388.
