An October 10, 2012 television program on Nova dealt with Viking swords and their origins.  Some of the metallurgical techniques can be traced back to ancient India.

India possessed an advanced knowledge of metallurgy.  The pillar known as the Iron Pillar of Delhi, built by Chandragupta II Vikramaditya (375–413), stands at the Red Fort, where it has stood for over 1,700 years, and although made of iron, it has never rusted. No one knows how this could be possible.

The Vikings made certain swords from what was called Damascus steel; imported to the Middle East from India. In India it was known as Wootz steel. The Vikings, as we know, were a warlike people, who made a practice of raiding and pillaging, so swords were important to them. Like many ancient peoples, the Vikings worshipped their weapons.  The only way to gain admission to the Viking heaven, Valhalla, was to die…