Compare 1 Enoch 64:2 and 2 Enoch 18:3

... One of the pieces of evidence that catches the eye here is the peculiar title “prince” by which the passage describes the leader of the incarcerated angels. Already Robert Henry Charles noticed that although the passage found in chapter 7 does not directly name Satanail as the leader of the rebellious angels, the reference to the fact that they “turned away with their prince” (Slav. с князем своим) invokes the similar terminology applied to Satanail later in chapter 18:3 which tells that the Watchers (Grigori) turned aside from the Lord together with their prince (Slav. с князем своим) Satanail. Charles’ suggestion appears to be plausible, and in light of the identical formulae attested in chapter 18 it is possible that the Satanail tradition is already present in 2 Enoch 7. If it is so, here for the first time in 2 Enoch the chief negative protagonist of the Adamic lore becomes identified as the leader of the fallen Watchers. ...