Advent texts: The Silmarillion

"Now Fingolfin, King of the North, and High King of the Noldor, seeing that his people were become numerous and strong, and that the Men allied to them were many and valiant, pondered once more an assault upon Angband; for he knew that they lived in danger while the circle of the siege was incomplete, and Morgoth was free to labour in his deep mines, devising what evils none could foretell ere he should reveal them.  This counsel was wise according to the measure of his knowledge; for the Noldor did not yet comprehend the fullness of the power of Morgoth, nor understand that their unaided war upon him was without final hope, whether they hastened or delayed."
Of the Ruin of Beleriand and the Fall of Fingolfin

"In those days Maedhros son of Feanor lifted up his heart, perceiving that Morgoth was not unassailable...  Then in the plains of Anfauglith, on the fourth day of the war, there began Nirnaeth Arnoediad, Unnumbered Tears, for no song or tale can contain all its grief... The field was lost; but still Hurin and Huor and the remnant of the house of Haldor stood firm with Turgon of Gondolin, and the hosts of Morgoth could not yet win the pass of Sirion.  Then Hurin spoke to Turgon, saying 'Go now, Lord, while time is!  For in you lives the last hope of the Eldar...'  Last of all Hurin stood alone.  Then he cast aside his shield, and wielded an axe two-handed; and it is sung that the axe smoked in the black blood of the troll-guard of Gothmog until it withered, and each time that he slew Hurin cried 'Aure entuluva!  Day shall come again!'  Seventy times he uttered that cry; but they took him at last alive by the command of Morgoth..."
Of the Fifth Battle: Nirnaeth Arnoediad

"But at the last the might of Valinor came up out of the West, and the challenge of the trumpets of Eonwe filled the sky, and Beleriand was ablaze with the glory of their arms, for the host of the Valar were arrayed in forms young and fair and terrible, and the mountains rang beneath their feet...  Then an end was made of the power of Angband in the North, and the evil realm was brought to naught..."
Of the Voyage of Earendil and the War of Wrath