Lactantius

“ XV.—Of the Corruption of Angels, and the Two Kinds of Demons.
When, therefore, the number of men had begun to increase, God in His forethought, lest the devil, to whom from the beginning He had given power over the earth, should by his subtilty either corrupt or destroy men, as he had done at first, sent angels for the protection and improvement [1] of the human race ”

“ Thus from angels the devil makes them to become his satellites and attendants. But they who were born from these, because they were neither angels nor men, but bearing a kind of mixed [4] nature, were not admitted into hell, as their fathers were not into heaven. Thus there came to be two kinds of demons; one of heaven, the other of the earth. The latter are the wicked [5] spirits, the authors of all the evils which are done, and the same devil is their prince. Whence Trismegistus calls him the ruler of the demons. ”

“ Therefore, while they abode among men, that most deceitful ruler [3] of the earth, by his very association, gradually enticed them to vices, and polluted them by intercourse with women. Then, not being admitted into heaven on account of the sins into which they had plunged themselves, they fell to the earth. ”