Who's sword was the sword in the stone?
It was Arthur's sword before Excalibur was. Arthur pulled one sword from the stone to earn his kingship, then later it (or whatever other sword he used at the time) got broken in battle, and the Lady of the Lake gave him Excalibur as a replacement.
Interesting. I'm not immensely familiar with the details of Authurian legend and its been quite a while since I've seen Excalibur