• Romans were the first to introduce system of international valid coinage.
• A main purpose of money was to relay news and announce victories won by the Roman army throughout the empire.
• Coinage could be used to spread information throughout the Roman Empire, to the Roman people.
• Coins also portrayed the emperor in the way he wanted the people to see him.
• Coins could be used to try to make the Roman people to believe something about the emperor.
• Emperors would all make coins congratulating themselves.
• Coins displayed slogans like "Roman Security," "Good Health," or "Virture."
• Famous coin message: Felix Tempus Reparatio which means "restoration of good time" or "the happy days are here."
• Emperors such as Caracalla and Geta made coins stated VICTORIAE BRITANNICAE- "for the victory in Britain."
• Trajan would use coins to make references to his Dacian Wars.
• Coins had to be mass-produced to satisfy the demands of the population.
• Coins are important to archaeologists because they tell about the emperor and the economical and political changes of the empire.
• It also told the circulation of money, about the inflation and prices of goods, and use of trade and communication throughout the empire.
• Augustus was the emperor who standardized mints into seven denominations.
• Coins were made out of metal such as gold, silver, brass, bronze, and copper.
• Mints were made and molten metal was poured into mold, which produced a number of coins at a time.
• Coins were then placed between two dies, then hit with a heavy hammer and 20,000 coins could be struck from a single die. (A die is an imprint of the coin.)

1 gold Aureus = 25 Denarii
1 silver Denarius = 4 Sestertii
1 brass Sestertius = 2 Dupondii
1 brass Dupondius = 2 Asses
1 copper Ass = 2 Semisses
1 copper Semis = 2 copper Quadrantes

http://www.stoke.gov.uk/museums/pmag/archaeology/romans/money.htm