One of the Twelve Swords from Fred Saberhagen's Book of Swords series.
Townsaver was left with Jord, the only one of the human helpers conscripted by Vulcan in the forging to survive. While the other's blood was used to quench the blades, Vulcan simply cut off Jord's right arm.
Like all the Swords, Townsaver has an identifying mark on the handle/hilt. In this case, a design that brings to mind the crenellations atop a defensive wall, with what looks like an arm holding a sword behind it.
The sword's power is the ability to defend non-combatants in a dwelling that is being attacked. Unfortunately, it does not care about the person wielding the weapon. In the series, the protagonist Mark's brother as well as the dragon hunter Nestor were killed while wielding Townsaver.
Townsaver was destroyed during the seige of Tassavalta when Vulcan engaged someone wielding Townsaver while Vulcan himself was wielding Shieldbreaker. Doomgiver was also likewise destroyed.