Genesis 6:1-4

So when men began to be multiplied vpon the earth, and there were daughters borne vnto them, Then the sonnes of God sawe the daughters of men that they were faire, and they tooke them wiues of all that they liked. Therefore the Lord saide, My Spirit shall not alway striue with man, because he is but flesh, and his dayes shalbe an hundreth and twentie yeeres. There were gyants in the earth in those dayes: yea, and after that the sonnes of God came vnto the daughters of men, and they had borne them children, these were mightie men, which in olde time were men of renoume.