There are a few related thoughts that I wanted to append to Leolaia's excellent thread. She mentions the symbolism of the number 70 and association with divine judgment and how this allows for a less than chronologically accurate use by authors using the motif. To this point we see Isa 23 prophecy of 70 years of desolation followed by restoration of the non-Israelite Tyre (aka the lifespan of a King).
Also notable of course is the Babylonian Inscription of Esarhaddon:
"Seventy years, the reckoning of its destruction which He had inscribed, the merciful God Marduke, as soon as his heart had calmed down, reversed the order (of the sign) and ordered it's resettlement after eleven years."
The cuneiform text seeks to rationalize Babylon's destruction by Sennacherib as an act of punishment by Marduke but yet explains the early restoration of the city as an act of compassion on Marduke's part. It suggests the presence of a number motif of "70" in wider use in the ancient Near East.
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Moving away from the numbers stuff, the apocalyptic chapters of Daniel's involve "visions' of a procession of empires/kings that rule the world. The writer of Daniel had inherited this motif as well, he/they may have even inherited the highly questionable idea of the Medes being the immediate predecessor to the Persian empire.
2013_Hdt. Median Logos_IrAnt_AZ.pdf
This may explain the beast motif in Rev.13:1-10 in which the Roman beast is clearly a conglomeration of all the beasts of Daniel rather than a 5th. A total of 7 heads and ten horns representing the sum of the power of the preceding empires. Daniel's beasts with their total of 7 heads and 10 horns are here merged into a single one representing Rome but at the same time all the previous. Another new concept is that the true source of the power (puppet master) of Rome was believed a spirit power, the ancient chaos dragon with matching number heads and horns called 'Satan'.