Sigmund
Sigmund was the son of Volsung and Ljod (Hljod). He was brother of Signy (his twin), and nine other brothers; no names were ever given for Sigmund's brothers.
Sigmund was the only person who could draw out the magic sword Gram (Balmung) from the great tree Branstock (very much like Arthur drawing Excalibur from a rock). The sword allowed the man who wielded the sword to win all of his wars. Siggeir, who was his father's guest and had proposed marriage to his sister, wanted to buy the sword. Sigmund refused. The refusal angered Siggeir into plotting to destroy Volsung and his family.
His father and brothers were killed. Sigmund survived, and together with his sister, they sought vengeance against Siggeir. Sigmund had unknowingly slept with his sister (Signy was disguised as a witch). Sigmund was also aware that Sinfjotli was really his son. With Sinfjotli's help, Sigmund destroyed Siggeir and his people by setting the palace on fire, letting no one to escape except Signy. Signy however told Sigmund the truth about their son, before returning to the burning house.
Sigmund returned to his land with Sinfjotli, and became king of the Huns. Sigmund married Borghild and became the father of Helgi and Hamund. Borghild hated her stepson and poisoned Sinfjotli. Sigmund banished Borghild for murder and sought a new wife. Sigmund fell in love with Hjordis, daughter of Eylimi. Lyngi (Lyngvi), son of Hunding, was another suitor of Hjordis. Lyngi was jealous when he lost to Sigmund, who was an older man. Lyngi led his father's army against Sigmund and Eylimi.
In the battle, Sigmund's father-in-law was killed. Odin, who gave the sword to Sigmund, shattered the sword in two. Sigmund was mortally wounded, and his army was defeated. Hjordis, who was pregnant with Sigmund's child, found her husband. Sigmund asked Hjordis to collect the shattered blade of his sword and give it to their son when he needed a sword. Hjordis fled to Denmark and married its king, named Alf.
When Sigurd had grown, Hjordis gave the shattered blade to her son. With the sword called Gram (Balmung), Sigurd not only killed a dragon with this new sword, but he also avenged his father by killing Lyngi and his brothers, and destroying their army.
Note that in the Thiðrekssaga, Sigmund was the king of Tarlungland and he was the son of Sifjan. Sigmund had a son named Sigurd by his wife Sisibe, daughter of Nidung, the King of Spain. In the Nibelungenlied however, his wife was Sieglind.
In the Anglo-Saxon poem Beowulf, he was Sigemund the son of Waels, the slayer of a dragon (though in Norse and most German literature, it was his son Sigurd or Siegfried who had killed the dragon).
By Jimmy Joe