The Silver Branch was a staff formed from a cutting of Yggdrasil, also known as the World Tree or the Tree of Life. It was used to replace the dying Yggdrasil with its successor, the Silverbranch Tree, at the end of the Great War. 11 years after the Cataclysm, the Silver Branch has emerged in a new form from the new World Tree and has been entrusted to the care of Leon Alcibiates so that it can be used to cure the source of the Blood Fever.
The Silver Branch was originally created by the joint effort of Grady Silverbranch and Leon Alcibiates to fight Queen Adevia in the Grandbell Civil War in the Second Age. It was used by Leon and Grady to counter the combined efforts of all of Adevia's mages, allowing Despard Silverbranch to duel and kill Adevia.
The Cursed Earth of Yamato (formerly Miletos) was the driving force behind Yamatian expansionism in the Yamatian War and later the Great War in the Third Age. Leon Alcibiates was reborn with the help of Ayna Silverbranch who entrusted him with the Silver Branch and asked him to find its chosen bearer who could then cure the Cursed Earth as a prophecy foretold.
Leon eventually found the bearer who was none other than Geraud Aurelac whose body also occupied the spirit of Grady Silverbranch. Geraud/Grady transferred their lifeforce into the Silver Branch at the heart of the Cursed Earth on the Isle of Yggdrasil in the later years of the Great War. The Silver Branch was planted into the ground, which caused it to grow into a second World Tree known as the Silverbranch Tree, and the planting created another White Seal to protect the new World Tree from molestation.
The Fellowship of Maar Sul, including Leon Alcibiates, travelled to Yamato several years after the second World Tree's planting in order to find a means to heal the Blood Fever that was weakening the elves in Remon and was in the stages of spreading to the elven populations abroad as well. The spirit of Geraud/Grady appeared before the fellowship as the avatar of the Silverbranch Tree and gave them a new Silver Branch although with a warning: healing the Blood Fever might have unforseen consequences. The spirit also mentioned that the Silver Branch alone could not heal the Blood Fever; the fellowship would also need the power of the magic swords Dawn and Dusk to accomplish the task.