But, rather than cross swords with the slayer of a dragon, Gunnar offered the stranger his hand in friendship and sent for his sister to give him the cup of welcome.

While sojourning here with the Niblungs, Sigurd distinguished himself by athletic feats and, when war broke out, by conquering their foes.

These proofs of strength and daring captivated the heart of Gudrun, who, seeing Sigurd paid no attention to her, finally prevailed upon her mother to give her a love potion, which she offered to him on his return from one of his adventures.
"He laughed and took the cup: but therein with the blood of the earth Earth's hidden might was mingled, and deeds of the cold sea's birth, And things that the high gods turn from, and a tangle of strange love, Deep guile, and strong compelling, that whoso drank thereof Should remember not his longing, should cast his love away, Remembering dead desire but as night remembereth day." No sooner has this potion been quaffed than our hero, utterly oblivious of earlier promises to Brynhild, sued for Gudrun's hand, and was promised she should be his bride if he helped Gunnar secure Brynhild.
In behalf of his future brother-in-law--whose form he assumed--Sigurd once more rode through the flames, and, although haunted by vague memories of the past, wrested from Brynhild the magic betrothal ring he had given her, and claimed her as bride.

Compelled by fate to wed any man who rode through the flames to claim her, Brynhild reluctantly obeyed Sigurd--whom she did not recognize--and was duly married to Gunnar, king of the Niblungs.

But, on perceiving Sigurd at his court, she vainly strove to make him remember her and his vows, and was filled with bitter resentment when she perceived his utter devotion to Gudrun, his present bride.
Meantime, although Gunnar had secured the wife he coveted, he was anything but a happy man, for Brynhild would not allow him to approach her.