A major portion of Paradise Lost is narrated by the angel Raphael. He begins his story with a celebration in heaven. In the chronology of PL, and even possibly the Bible, this can be said to be the earliest recorded event—before the creation of the world, and before the war in heaven.
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6 Yet have I set my king upon my holy hill of Zion.

7 I will declare the decree: the LORD hath said unto me, Thou art my Son; this day have I begotten thee.

1 God, who at sundry times and in divers manners spake in time past unto the fathers by the prophets,

2 Hath in these last days spoken unto us by his Son, whom he hath appointed heir of all things, by whom also he made the worlds;

3 Who being the brightness of his glory, and the express image of his person, and upholding all things by the word of his power, when he had by himself purged our sins, sat down on the right hand of the Majesty on high:

4 Being made so much better than the angels, as he hath by inheritance obtained a more excellent name than they.

5 For unto which of the angels said he at any time, Thou art my Son, this day have I begotten thee? And again, I will be to him a Father, and he shall be to me a Son?

6 And again, when he bringeth in the firstbegotten into the world, he saith, And let all the angels of God worship him.