There are quite a few legendary artifacts of antiquity. Excalibur is a very good item to research. I also know there is a dagger referred to by Erasmus Desiderius in his work "The Christian Soldier's Handbook." I believe it to be reforged from the infamous Toledo-Salamanca. Also there are fictional works as well, have you ever watched the Highlander? Duncan McLeod wields the legendary Katana of ancient Japanese lore. It has a white ivory handle with a lions open mouth carved on the hilt. It is rumored that this weapon requires innocent blood everytime it is unsheathed. I am writing a wiki on legendary artifacts at www.legendarystory.wikia.com, feel free to add your input but please substantiate your research before adding anything to my story. I am going to write a book in the future.