Study › Runes & Norse › Sigmund and Sinfjötli

Sigmund is the greatest of the Volsungs before his son Sigurd, the only man who could draw the sword Odin thrust into a tree. With his son Sinfjötli he ran as a wolf, and both were taken by Odin in the end.
Who are Sigmund and Sinfjötli?
Sigmund is the father of Sigurd and the greatest of the Völsungs before him. The Völsunga saga tells how, at his sister Signý's wedding feast, a one-eyed stranger — Odin — thrust a sword into the tree Barnstokkr in the middle of the hall, and said it would belong to whoever could draw it out. Only Sigmund could. His son Sinfjötli was born to avenge the family, and father and son lived wild in the forest; once they put on wolf skins they found and could not take them off, and ran as wolves until the skins could be burned. Sinfjötli died of poisoned ale, and Sigmund carried his body to a fjord, where a ferryman took it into his boat and vanished — Odin, come for his own. At the end of his life, in his last battle, Sigmund's sword broke on Odin's spear. In the poem Eiríksmál, it is Sigmund and Sinfjötli whom Odin sends to greet a new king at the doors of Valhalla.
His sword became Gram; they greet Eric Bloodaxe at the doors of Valhalla.
Questions
What sword did Sigmund draw?
The one Odin thrust into the tree Barnstokkr. Its shards were later forged into Gram.
Who is Sigmund's son?
Sinfjötli, and later the hero Sigurd.