loseth said:
I know it sounds implausible, but believe it or not, the idea that the 'dark ages' or 'feudal age' was a time when barter reigned supreme and coins were meaningless is actually a popular myth rather than a historical reality. After Rome ceased to control its territory in the West directly (i.e. the 'fall' of the Roman Empire), the new Germanic rulers of the Roman West largely continued business as usual, minting and spending coins just as the Romans had (see a couple of examples
here). Even in Britain, where things really were fairly 'dark,' there was plenty of coinage about. Barter will be more important in a PoL setting than in a non-PoL one, but a barter economy and a coin economy are not mutually exclusive.
Check out the example I gave earlier of the Medieval Baltic. It really was as PoL as I claim, and a coin economy operated just fine. As long as you're strong enough to protect your points of light and the trade routes that connect them (as the monks militant and warlike pagan nations who ruled the Baltic were), then coins will equate to spending power even in a bandit-ridden war-torn land of mostly untamed wilderness.
Not quite. The link you gave is for Merovingian coinage. There's a strong link between the closing of the Mediterranean due to the Moslem conquests and the destitution of the Merovingian monarchy - they made most of their money through the tonlieux (trade tariffs). This lead to an increase in power in the landed aristocracy, and the crown being controlled by "Mayors of the Palace", much like the Shogunate in Japan.
After the Merovingians lost power and the Carolingians took over, they ceased minting the gold Solidus and only minted the silver Denier. All sorts of things disappear from the records then: papyrus, oil, spices, etc. Trade, as it was known in the West, died. There's a definite case to be made, in fact, that this is when the Roman Empire really died in the West. Many people lived much as they had in the Empire up until this point, but everything changed when the Mediterranean economy was disrupted. For a single example, the large Roman latifundia (sort of like large farming planations) don't make nearly as much sense when there's little market for a cash crop.
The Baltic is also a special case, and you can't really apply information about them to the rest of Western Europe for the time period. They maintained a seagoing trade and more of what we would recognize as an economy, even though they didn't have any trade links with the Orient. However, the Viking invasions at the close of the Carolingian period ended their prosperity. Eventually the Vikings also revived trade in the Baltic, and actually forged the first semi-direct links the west had with the Orient through the trade along the Russian rivers.
I think a key portion of the whole Points of Light concept is the dearth of trade, though your point that currency never truly disappeared is accurate. When all you have is the intermittent peddler or emissary of a distant lord, information about the outside world is sparse. But if you're part of a regular economy, even a small part, you probably at least know where the product of your labor is going, and there's probably regular information going back and forth when the product is transported.
As such, I don't think Sengoku Jidai era Japan is a great example of the Points of Light concept. Neither is the middle or later Middle Ages. By the High Middle Ages trade had been revived and the Moslem stranglehold on the Mediterranean had been loosened. Heck, the Crusaders were able to get to the Levant by ship via Venice (which admittedly appears to at least have retained trade in the Aegean throughout the period, though probably not much farther), while in the 8th century it was said that the Christians could no longer float a plank upon the sea.
For references for the common reader, I recommend any of the numerous books on Charlemagne for flavor, and "Daily Life in the Age of Charlemagne" by Pierre Riche for details about the world if you can lay your hands on it.
For further reading for someone more interested in the period, Henri Pirenne's "Mohammed and Charlemagne" and Pierre Riche's "The Carolingians" are both great.
I also recommend Norman F. Cantor's "The Civilization of the Middle Ages" to anyone who's at all interested in the Middle Ages. It's highly readable and very accessible to even a novice in Medieval history.