The Great Bullion Famine, in mid-fifteenth century Europe, was a shortage of precious metals. It was largely driven by an unfavourable balance of trade with the Middle and Far East due to the shortage of goods, other than precious metals, with which to purchase goods such as spices, silk and cotton.
Numerous factors may have caused the Great Bullion Famine. In the 14th century, the Black Death ravaged Europe, killing over half of its population, and leaving many areas heavily depopulated and unable to meet previous levels of economic production. In addition, Europe had a long-running precious metal deficit in its trade with the Middle East and Asia, ever since the days of the Roman Empire. This is due to the fact that products from China and India such as spices, silks, and cotton, were very rare or completely unavailable in Europe, and thus highly valued - but Europe lacked as many goods to trade back to the east, and so relied on precious metals, which were always in demand due to their use in coinage, bullion, and luxury goods. This meant that in exchange for renewable eastern goods, Europe was trading away its non-renewable precious metals. Additionally, the price of goods was very low in Europe, making the trade deficit worse.
Note that Western Europe suffered a massive deflation during and subsequent to the fall of the Western Roman Empire. Exacerbating the (already long running) precious metal deficit with the East was the specie hoarding characteristic of deflation - a positive feedback loop. Feudalism is an indicator of this as monarchs resorted to paying retainers with land instead of specie, and tenants likewise paid rent with labour and commodity produce.
All this while the precious metal mines of Europe were in decline. Flooding and the lack of technology to deal with it prevented mining deeper where the veins were still rich.
Over the course of this millennium we see two significant upticks in economic activity, associated with two significant quantitative easings resulting from de-hoarding activities:
- Viking raids of Western Europe from circa 800 to 1000 C.E. put large quantities of precious metals hoarded by monasteries and churches back into circulation.
- The Fourth Crusade's sack of Constantinople in 1204 puts 900,000 silver marks (~450,000 pounds) into circulation.
More detail behind these links on Medieval Silver and Gold and on Medieval money.
For those inclined to think deeper on the associated economics and politics of the millennium 453-1453 - the growth and popularity of mercantilism in the centuries immediately following this period becomes more understandable:
a national economic policy designed to maximize the trade of a nation and, historically, to maximize the accumulation of gold and silver