Vastclaw Valley is a great, verdant valley in the Thunderlands of Ghyran. In the Age of Myth, the sylvaneth grew a shrine there honouring Eagderethil, the father of bladewillows, on the rocky isle in the centre of the Sorrowmere lake in the valley.
According to the myths and legends of the Thunderlands, the everbeast Fengarant somehow found Eagderethil stabbed in a paw like a thorn. Fengarant stomped a mad path across the realm, attempting to remove the thorn from his paw, until he finally stomped the ground so hard that his footprint made Vastclaw Valley and planted Eagderethil.
Age of Myth
The sylvaneth grow an enclave about the island where Eadgerethil grows. The bladewillow shrine's roots cover the island at the centre of the Sorrowmere, forming a nexus of life energy that affects the lands for hundreds of miles.
Age of Chaos
As Chaos spreads across the Mortal Realms, the sylvaneth of Vastclaw Valley and Eadgerethil are cut down and the valley becomes home to a succession of warlords who covet the defensible position of the island shrine and the bountiful lands of the valley, which is still affected by the lingering life magic. At the close of the Age of Chaos, the valley is under the control of the Ironjawz Megaboss Grolnok Gitstompa, who builds vast monuments to Gork and Mork in the valley.
Age of Sigmar
The sylvaneth discover that, over the centuries, Eadgerethil's dormant realmroots have leaked magic out into the Sorrowmere and formed a realmgate beneath the surface of the lake. Ancient Lharenthol of Clan Tethil of Harvestboon Glade makes an alliance with Drycha Hamadreth and her Outcasts and uses the realmgate to spring a surprise assault on the Ironjawz. While the Outcasts occupy the orruks' attention, Lharenthol drives his roots into the remains of the shrine at the centre of the isle, pouring life-giving magic into the shrine to revitalize both his allies and the valley itself, with bladewillows and thornvines growing explosively and impaling many orruks. Ultimately, Grolnok realizes the battle is lost and flees, while Eadgerethil begins to grow again.