Money & Trade
As Europe became more peaceful and orderly, people began to be more interested in buying things and demands for luxury items such as silks and gems increased. Trade grew and medieval merchants who used to be just peddlars became more properous and a rich merchant class emerged. The marketplace became the focus of many towns. New jobs were created in towns as well as new powerful estabilshments like banks. This had an negative effect on the old feudal system.
Coins in the Middle Ages
Medieval European coinage was standardized by Charlemagne around 800 AD when he conquered most of Europe. The standard Denier (Penny in English, Pfennig in German, Denaro in Italian) was a silver coin about the size of a US penny. It's thought that its value at the time was about that of a meal. For the next 4-500 years, most coinage in Europe followed this standard pattern. Most Medieval coins have a cross somewhere into the design. German and other eastern regions often incorporate an eagle into the design while English coins generally carry a crude portrait of the King. French coins will often show a monogram, castle, or cathedral.