MUST READ - about money
Ithaca Community Money (interview from 13 years ago!!)
In the 8th century, Charlemagne declared that 240 pennies or pfennigs should be minted from a pound of silver. A Carolingian pound was approximately 326 grams, so a single coin thus contained about 1.36 grams of silver. (Today, this amount of silver would cost about £0.40 sterling.)
Medieval Brakteaten are one-sided embossed silver medieval hollow-penny coins with a diameter of 30 to 65 mm. That area had plenty of space for high-quality artistic performances.
Brakteaten were from the middle of the 12th Until the 14th century Century
almost the entire German-speaking countries
(with the exception of the Rhineland, Westphalia and the Central region),
the dominant regional coin.
The term is not contemporary ... used first time in the 17th Century
for this coin type.
In some regions, the Brakteaten periodically were recalled
(in Magdeburg in the 13th century several times a year),
thus had to be swapped for new Brakteat money.
They were, for example, three new four ancient coins to change.
The withheld 4th coin has been described as a struck money
and was often the only tax revenue of coin issuer (renovatio monetae).
The "struck" led to the money loosing value and the velocity of money was raised.
By recalling the money it was unattractive as a capital
and its role as a universal medium of exchange
has been strengthened (double function of money).
Financial wealth to possess was unattractive,
so investing in property, which a recovery of the craft
and art has brought.
The German cities were not interested in such loss
and then introduced from 1413 a so-called "penny Eternal",
which was the beginning of the end of Brakteat-age
and normal thicker double-sided coins returned.
This was a google translation from the german wikipedia article
it would be nice if someone would include the "negative interest" viewpoint
into the english article: