The Vulsung follows the Saga of King Sigurd. This story Draws similarity between between the Arthurian Legends and the saga. The Saga of the Vulsung describes a sword being removed from a Tree, not too dissimilar to, Yggdrasil. just as the sword was named Excalibur in the Arthurian Legend, the name of the sword in The Saga of the Vulsung is known as Gram.
The Arthurian timeline is believed to date back to the roughly 700's CE but the modern story and aspects known today are dated to the 1200's roughly.