A previous theory held that the swords may have their origin in the Middle East or Asia, but surprisingly it seems the materials were sourced closer to where they were found, in Central Europe. At the time the Ulfberht swords were forged (approximately 800?"1000 A.D.), equally perplexing swords made of a substance called Damascus steel were being produced in the Middle East out of a raw material, known as Wootz steel, from Asia. Both Damascus steel and the Ulfbehrt's so-called "crucible steel" had high amounts of carbon.