Clement of Alexandria - 70 Year Desolation of Jerusalem

For many centuries it has been accepted as a fact that Jerusalem lay desolate and uninhabited for seventy years after Nebuchadnezzar carried its inhabitants off to Babylon. In recent years some have come to reject what the Bible says and accept based purely on what archaeology has been able to find that it was only 49 years. They claim that the Bible does not say that Jerusalem would be desolate for 70 years, despite Daniel stating the following:

Dan 9:2  in the first year of his reign I, Daniel, understood by the books the number of the years about which the word of Yahweh came to Jeremiah the prophet, for the accomplishing of the desolations of Jerusalem, even seventy years.

Once again, we see an "Early Church Father", Clement of Alexander, supporting the position of Jehovah's Witnesses that the city of Jerusalem lay desolate a full 70 years and not merely 49:

And in the twelfth year of the reign of Zedekiah, forty years before the supremacy of the Persians, Nebuchodonosor made war against the Phœnicians and the Jews, as Berosus asserts in his Chaldæan Histories. And Joabas,  writing about the Assyrians, acknowledges that he had received the history from Berosus, and testifies to his accuracy. Nebuchodonosor, therefore, having put out the eyes of Zedekiah, took him away to Babylon, and transported the whole people (the captivity lasted seventy years), with the exception of a few who fled to Egypt.

This quote is quite interesting as it gives us two separate points for the dating of the exile. Firstly he tells us that the twelfth year of the reign of Zedekiah was forty years before the "supremacy of the Persians", which is about 559 BC when Cyrus II took over from his father Cambyses I becoming the first true king of the Persian Empire. This would mean that the twelfth year of Zedekiah could be no later than 599 BC and not 587/6 as is generally accepted.

He goes on to repeat the seventy years of desolation later:

On the completion, then, of the eleventh year, in the beginning of the following, in the reign of Joachim, occurred the carrying away captive to Babylon by Nabuchodonosor the king, in the seventh year of his reign over the Assyrians, in the second year of the reign of Vaphres over the Egyptians, in the archonship of Philip at Athens, in the first year of the forty-eighth Olympiad.

The modern chronology gives us a date of about 588/7 BC for all of these events, but here we encounter multiple problems for the modern chronology, firstly the date of the supremacy of the Persians is known to be approximately 559 BC with the 12th year of Zedekiah being forty years prior, or no later than 599 BC. Secondly and he gives us the end date and length of the captivity, conforming with Daniel:

The captivity lasted for seventy years, and ended in the second year of Darius Hystaspes, who had become king of the Persians, Assyrians, and Egyptians; in whose reign, as I said above, Haggai and Zechariah and the angel of the twelve prophesied. And the high priest was Joshua the son of Josedec. And in the second year of the reign of Darius, who, Herodotus says, destroyed the power of the Magi, Zorobabel the son of Salathiel was dispatched to raise and adorn the temple at Jerusalem.

Darius became king of the kingdoms listed in 539 BC at the conquest of Babylon, his second year was therefore 537 BC. Clement, following Josephus a hundred years earlier and Berossus  who wrote c.290-278 BC or 300 years earlier and only about 200 years after the fall of Babylon, tells us that the exile lasted a full seventy years and finished in the second year of the reign of Darius or 537. Therefore, following Clement of Alexander, the exile could not have started later than 607 BC.

To accept the date of 587/6 as the beginning of the exile we have to assume that this hefty list of sources cited and quoted by a man who lived only 600 years after the date is completely wrong and that the sources he used, some less than 300 years after the time, were also defective. Worse we have to assume that when he, Daniel and God all say the exile and desolations of Jerusalem lasted "seventy years" they were all essentially lying.