クレティアン・ド・トロワ
In the 1170s, Chrétien de Troyes mentions the forest of Brocéliande in his Arthurian romance, "Le Chevalier au lion". While in Brocéliande, Yvain pours water from a spring into a stone, causing a violent storm to erupt. This in turn summons the knight Esclados le Ros who defends the forest.