Before I begin, I would like to say how much I am enjoying the NLT Study Bible and the ESV Study Bible. If you have not purchased these yet, what are you waiting for? You can have both for less than $60 if you do some internet shopping. A great study Bible with a formal translation like the ESV and a great study Bible with a dynamic translation like the NLT. Both are great tools and I am enjoying putting them together. I first began this project thinking that these comparisons would help readers decide which one to buy. I think you should buy both and place them on your desk where you will use them daily. They are both very well done.
Revelation 17:9-11 is one place in the book where I think we are given information that helps us know when the book was written. First, the text and then the study notes.
9 This calls for a mind with wisdom: the seven heads are seven mountains on which the woman is seated; 10 they are also seven kings, five of whom have fallen, one is, the other has not yet come, and when he does come he must remain only a little while. 11 As for the beast that was and is not, it is an eighth but it belongs to the seven, and it goes to destruction. (ESV)
Rev. 17:9—11 Rome, which then had “dominion over the kings of the earth” (v. 18), rests on seven mountains (or seven hills; cf. Introduction to Romans: The Ancient City of Rome). In prophetic imagery, mountains symbolize the seat of power (Jer. 51:24—25; Dan. 2:35, 44—45). The beast’s seven heads, symbolizing both mountains and kings, show its power over earth-dwellers whose names are not in the book of life. Efforts to identify in history the five fallen kings (or kingdoms), the sixth (current) king, a seventh (future) king who would reign briefly, and the eighth that belongs to the seven have yielded conflicting conclusions (proposals include several Roman emperors, several world empires, or simply numerical symbols standing for all worldly kingdoms that culminate in the beast). Even if they cannot be identified specifically, these details send the message that, although the dragon and beast’s final assault has not yet begun, their “time is short” (Rev. 12:12), for the beast goes to destruction.
NLT Study Bible:
17:10-11 five kings have already fallen: If these kings represent Roman emperors, and the starting point for numbering them is the switch from a republic to an empire with Augustus (29 BC–AD 14), then the fifth in line would be Nero (AD 54—68), the sixth would be Vespasian, and the seventh would be Titus. The eighth king would then be Domitian. – that was, but is no longer: Early commentators argued that Domitian was an embodiment of Nero’s spirit (see note on 17:8). – like the other seven: This apparently invincible ruler was also headed for destruction.
I think these notes show how both study Bibles are useful. The ESVSB give some of the general theories behind the text, but nothing specific. The NLTSB gives a specific interpretation for the text. For me, I have not come across a better answer for interpreting this text than to count the Roman emperors. Five kings have already fallen (Augustus through Nero). The sixth that now reigns would be Vespasian. Titus will be the seventh (who finished the destruction of Jerusalem) and Domitian will be the eighth (who persecuted Christians), but will be like others, and will be destroyed.