§ Of the Return of the Noldor The Silmarillion

Yet cause he had for great joy, though it was hidden from him for a while. For Fëanor, in his wrath against the Enemy, would not halt, but pressed on behind the remnant of the Orcs, thinking so to come at Morgoth himself: and he laughed aloud as he wielded his sword, rejoicing that he had dared the wrath of the Valar and the evils of the road, that he might see the hour of his vengeance. Nothing did he know of Angband or the great strength of defence that Morgoth had so swiftly prepared: but even had he known it would not have deterred him, for he was fey, consumed by the flame of his own wrath. Thus it was that he drew far ahead of the van of his host; and seeing this the servants of Morgoth turned to bay, and there issued from Angband Balrogs to aid them. There upon the confines of Dor Daedeloth, the land of Morgoth, Fëanor was surrounded, with few friends about him. Long he fought on, and undismayed, though he was wrapped in fire and wounded with many wounds; but at the last he was smitten to the ground by Gothmog, Lord of Balrogs, whom Ecthelion after slew in Gondolin. There he would have perished, had not his sons in that moment come up with force to his aid; and the Balrogs left him, and departed to Angband.