How do you reckon the start date of the 70-year Babylonian captivity?
An emailer notes the captivity lasted 70 years and ended with the decree of Cyrus in 539 BC, but the major deportation and the destruction of the first temple came only about 50 years before Cyrus, and asks how to reckon the start date given that Daniel was deported earlier.
Answer
Those dates are difficult for a lot of people. The way it is usually done is that you take the first date as the beginning of the seventy years, especially because Cyrus comes on the scene exactly in 539 BC. The deportation happened in two phases: the first, initial deportation in 609 BC, and the major deportation in 587 BC, when Jerusalem and the first temple were destroyed. You count from the first date, 609, because you have to account for the people already carried off to Babylon between 609 and 587; they are there, so that period is part of the seventy years. From 609 to 539 BC gives you the span, ending with the decree of Cyrus, and Cyrus's date of 539 is fixed, so you have to measure around it. Just remember there are two phases, one in 609 and one in 587, so about twenty-two years of people were already in Babylon, and that twenty-two has to be counted as part of the seventy.