Archaeological excavations show the importance of iron swords: During the tumulus period, the power of the great king (later emperor) expanded. Myths and archaeological findings attest to the introduction of metallurgy from the continent and subsequent production of iron weapons which resulted in 1) the unification of the country by a great king, 2) the construction of huge tumuli by the ruling class to show their prestige, and 3) the worship of the iron sword and related myths about its power. Such worship of iron swords is told about the Scythians by Herodotus. In the Arthurian legends, the sword Excalibur is the source of the power and prestige of King Arthur. The worship of the ironsword as a divinity might have spread from the Scythians to both ends of the Eurasian continent, west to the Celts and east to the Japanese.