The Queen Mother of the West, Xiwangmu, was the most prominent female deity in early Chinese mythology. The roots of her legend may go back to high antiquity. The name Ximu, "Mother of the West," appears in Shang-dynasty oracle bone inscriptions; this has led some scholars to believe that worship of this goddess already existed before the eleventh century B.C.E. In the writings of Eastern Zhou (770–256 B.C.E.) philosophers, Xiwangmu is described as timeless and deathless. During the Western Han period (206 B.C.E.–9 C.E.), she was further linked with the concept of a western immortal land. Shortly before the beginnning of the Common Era, she was worshipped both at the imperial court and among the masses. Her image became standard decoration for tombs and funerary shrines. The popularity of the Xiwangmu cult derived from the search for immortality, which rose to an unprecedented height during the Han dynasty. In popular belief, Xiwangmu was the deity who controlled the secret of immortality. She was omnipotent, able to bless people with wealth and children, and especially efficacious in helping people escape from worldly troubles. She was said to live on the summit of the immortal mountain Kunlun, where trees of deathlessness grew and the water of deathlessness flowed. There she was seated on her dragon-and-tiger throne and accompanied by fairies and divine animals. She appears on such a throne in the center of this lamp flanked by the sun and the moon symbolizing the two cosmic forces, yin and yang, and attended by three of her acolytes: a rabbit pounding the elixir of immortality, a three-legged bird, and a nine-tailed fox. Below her, two supplicants with staffs kneel in front of an open door, perhaps an entry to the realm of the immortals over which she was thought to preside. Surmounting the image of the Queen Mother is a drum on the back of a feline creature capped by a canopy-parasol. Two mounted drummers are on either side, and below them are two cup-bearing attendants on the backs of tigers. Two more lamp cups are to either side of the figure of Xiwangmu. The assemblage is supported by an ursine-like creature standing on the back of a giant tortoise. Hybrid creatures support four more lamp cups along the outer perimeter, two on each side. The whole composition suggests the western immortal mountain Kunlun, which was thought to be held up on the back of a tortoise. In its axiality, the lamp takes on the properties of an axis mundi.