A “coinage” used in The Middle Ages (which also traces it's origins to after the Fall of Rome), The Solidus was also known as The “Solado” in Italy and The “Sou” in France. The Solidus was first introduced by Emperor Constantine as his “first “Gold” coin around the early 3rd Century A.D. It weighed 4.55 grams. By the 12th Century, The Solidus (by know regulated to France), was a Silver coin.