At that Perceval turned away and mounted and set off. He began to climb a mountain, and when he reached the top he sat still on his horse and gazed up and down, and saw the whole country was scorched and burnt. He couldn’t believe his eyes: there wasn’t a castle, town or house left standing. He was amazed; and then, reflecting, he realised the demon had told him the truth: he had indeed destroyed the land.

Gerbert's Continuation of Perceval