It is assumed that the Rowan Tree was in existence when Merlin met Nimueh on the Isle of the Blessed because, according to Morgause, it lies at the "heart" of the Isle of Blessed (Le Morte d'Arthur). During the Great Battle for Camelot, Morgause gave Morgana a staff carved from the wood of the Rowan Tree to allow her half-sister to resurrect several skeletons using necromancy. Later Merlin destroyed the staff causing the skeletons to collapse (The Tears of Uther Pendragon). It is assumed that the Rowan Tree appeared around the time when the Dorocha were released (The Darkest Hour).