A long time ago the dragon Ostreverg ravaged and plundered the sacred Temple of Freya on the Skellige Islands. Three brothers, the sons of a jarl, vowed to recover the goddess' relics. The priestesses granted them diagrams of three ancient suits of armor so that they would be able to face the dragon's formidable fangs and devastating breath of fire. The smith Sigurd Ironlord forged the sacred armor for them.
[…] They say the eldest brother did not take part in slaying the dragon. He fled in terror when he saw the beast, leaving his brothers to perish in the flames. Since he was the first to take the oath before the priestesses and the one to convince his brothers to do the same, he became known as the Oathbreaker. Like the two other brothers, he was cursed. As the anathema was worded, he would live as long as he wore his complete outfit.
[…] The Oathbreaker died at the hands of the middle brother. A coward, he was fleeing his would-be murderer and removed his boots to sneak away unnoticed. The prophecy was fulfilled when he was pierced with a sword as he sought refuge in the waters of the Pontar. They say someone on the Aedirnian bank of the river found his possessions, including the diagrams of the Oathbreaker's Outfit, which remains cursed.