The medieval Legend of Sir Percival portrays a pure but naive knight. Because of his purity, Percival finds the castle of the keeper of the grail, Anfortas. But because of his naiveté, he fails to ask Anfortas about his illness. This question would have released him and made Percival the new keeper. Alas, he keeps his mouth shut and has to leave the castle.
This leads to Percival travelling around quite a bit, hoping to find a clue as to how to obtain the grail. The series of invasions, I am planning to do, sort of presents the lost episodes of this journey. Episode one is set in the woods of Lacravur.
Here Percival hunts a great boar and kills it. Only the boar then turns into an old man an utters a curse. Percival then encounters some woodcutters, who tell him that the boar was the former lord of Lacravur. He was turned into a boar by his wife, who is a witch, for cheating on her. Yet she protected him with a curse from hunters. Anyone, who would kill the boar, she announced, would bring upon him the rage of the forest. He wouldn't be able to leave the forest and would be hunted himself by the creatures of the wood.
Apparently the only way to escape the spell is to cut down enough trees to weaken the magic power of the wood. Percival thus strikes a deal with the woodcutters to help him escape. He also learns from them that there are bandits in the woods who have a haunt for ale. They might be willing to help Percival against the army from the wood, if he only offers them a steady supply.