Pseudepigrapha

1 Enoch 6:2

1 And it came to pass when the children of men had multiplied that in those days were born unto them beautiful and comely daughters. 2 And the angels, the children of the heaven, saw and lusted after them, and said to one another: 'Come, let us choose us wives from among the children of men and beget us children.' 3 And Semjâzâ, who was their leader, said unto them: 'I fear ye will not indeed agree to do this deed, and I alone shall have to pay the penalty of a great sin.' 4 And they all answered him and said: 'Let us all swear an oath, and all bind ourselves by mutual imprecations not to abandon this plan but to do this thing.' 5 Then sware they all together and bound themselves by mutual imprecations upon it.

Date: 200-50 B.C.E.
* Dates are based on scholarly estimates

Archelaus Acts of the Disputation with Manes 32

Acta Archelai

And certainly whosoever will, may keep the commandments; and whosoever shall despise them, and turn aside to what is contrary to them, shall yet without doubt have to face this law of judgment. Hence also certain of the angels, refusing to submit themselves to the commandment of God, resisted His will; and one of them indeed fell like a flash of lightning upon the earth, while others, harassed by the dragon, sought their felicity in intercourse with the daughters of men, and thus brought on themselves the merited award of the punishment of eternal fire. And that angel who was cast down to earth, finding no further admittance into any of the regions of heaven, now flaunts about among men, deceiving them, and luring them to become transgressors like himself, and even to this day he is an adversary to the commandments of God.

Date: 313-348 C.E.
* Dates are based on scholarly estimates