Medievalists are always talking about the great expansion of European agriculture in the high Middle Ages, and now a study of pollen from Poland puts some good science behind these assertions. Pollen from the moat of Malbork Castle in Gdansk, Poland, and some nearby bogs, measures the decline of forest and the rise of cleared land and rye fields. In AD 1050, the area was mostly forest. Clearing began in earnest in the 12th century and continued vigorously through the 13th, and by 1400 it was essentially complete. Only managed woodlots survived.
Malbork, the largest castle in Europe, was begun by the Teutonic Knights in AD 1280. This order was founded in 1224 to forcibly convert the people of Prussia to Christianity -- why should German knights go all the way to Palestine, they reasoned, when there were plenty of pagans to fight so much closer to home? The Teutonic Knights eventually established what amounted to an independent kingdom stretching along the Baltic Coast through modern Poland and Lithuania.
The Prussians resisted conversion for more than a century. It seems that they regarded their paganism as a key part of their identity, and remaining pagan was for them a sign of their independence from the encroaching Germans, Poles and Swedes. Only hints and fragments of their religion survive. The fragments include lists of gods and a description by a Renaissance historian of the Prussian sanctuary at Romuva, said to include idols of three leading gods, a great tree, and perpetual fires.
Our written sources emphasize male gods, but archaeologists mainly find female images like the one above, generally called "hags," and nineteenth-century folklorists found many stories in the region of powerful witches.
To get back to that pollen study, its authors associate the land clearances with the arrival of the Teutonic Knights. If so, then perhaps the Prussians practiced a less intensive form of agriculture, possibly slash and burn, which incidentally kept them moving about in the marshes and forests and made them harder to control. For them, the transition to a more productive economy also helped to break their independence and incorporate them more fully into the political and religious life of Europe.