The power of transforming others into wild beasts was attributed not only to malignant sorcerers, but to Christian saints as well. In other tales the divine agency is even more direct, while in Russia, again, men supposedly became werewolves when incurring the wrath of the Devil.

In 1692, in Jurgenburg, Livonia, Thiess testified under oath that he and other werewolves were the Hounds of God. He claimed they were warriors who went down into hell to do battle with witches and demons. Their efforts ensured that the Devil and his minions did not carry off the grain from local failed crops down to hell.

Thiess was steadfast in his assertions, claiming that werewolves in Germany and Russia also did battle with the devil’s minions in their own versions of hell, and insisted that when werewolves died, their souls were welcomed into heaven as reward for their service. Thiess was ultimately sentenced to ten lashes for Idolatry and superstitious belief.

In the ocean sea, on the island of Buyán, in the open plain, shines the moon upon an aspen stump, into the green wood, into the spreading vale.

Around the stump goes a shaggy wolf; under his teeth are all the horned cattle; but into the wood the wolf goes not, in the vale the wolf does not roam.

Moon, moon! Golden horns! Melt the bullet, blunt the knife, rot the cudgel, strike fear into the man, beast, and reptile, so that they may not seize the grey wolf, nor tear from him his warm hide.

My word is firm, firmer than sleep or the strength of heroes.

– A wizard’s zagovór from Songs of the Russian People

Not all Slavic werewolves were reputed to be the result of a voluntary transformation. There are numerous accounts such as spurned witch’s curse in Poland, or the White-Russian story of the wedding party transformed into wolves, magpies and a cuckoo for the bride.

There are some interesting specifics on this last type of transformation:
“In order to produce such an effect as this on a wedding party, the hostile wizard, it is generally believed, must girdle each member of it with a leather strap or piece of bast, over which unholy spells have been whispered.”

Or even more simply:
“According to a Ruthenian story, however, a witch once gained her end by simply rolling up her girdle, and hiding it beneath the threshold of the cottage in which the wedding festivities were being held. Every one who stepped across it immediately became a wolf.”

Top image by Lucas Cranach the Elder from the 15-16th centuries.
Middle image Hunting and display of the wolf of Ansbach by unknown author from around 1685.
Bottom image via Wolfgang Schild – Die Geschichte der Gerichtsbarkeit. Vom Gottesurteil bis zum Beginn der modernen Rechtsprechung, Hamburg: Nikol Verlagsgesellschaft 1997 S. 67 ISBN 3-930656-74-4. Lizenz von: Verlag Georg D. W. Callwey 1980 from a 1685 image.

Top quoted text via Wikipedia.
Bottom quoted text via William Ralston’s on Google Books. Also available on Amazon.