*This is the period of the Divided Kingdom which is the most complex because of synchronisms (links) between Judah and Israel and their different ways of measuring time (such as whether it is Accession Year reckoning or not, and whether Nisan or Tishri is the first official month of a king's reign).
Other technical complications are:
*SYNCHRONISMS: e.g: "King A of Judah began to reign in the 5th year of King B in Israel and reigned 13 years." *INTERREGNUMS: This are times when there was no king on the throne (maybe too young).
*CO-REGENCIES: - to secure his son’s succession to the throne a king will have his son on the throne with him (e.g: David & Solomon).
The usual practice was to give the length of a king’s sole reign. So even when there was a co-regency his reign would be counted from when the previous king died. The synchronism however usually gave the time the king began to reign even if it was during his father’s lifetime. This resolves many apparent contradictions.
*The key chronology to follow is JUDAH (the Messianic line is through the kings of Judah) which is relatively straightforward, but to fine-tune it, we need to track Israel’s chronology also.
*Periods of 390 years and 40 years in Ezekiel 4 are helpful in confirming the chronology.
*Unreckoned time - Judah’s Captivity in Babylon lasted 70 years from 607 BC.
This was ended by the Cyrus Decree of 537 BC (from 620BC onwards we are now into reliable recorded history).
*This was followed later by a decree by Artaxerxes in 458 BC to reestablish the city and its government (Ezra 7). As we will see, this Decree marks the end of this Great Jubilee Cycle and the beginning of the next one (Daniel 9:24).
*The total length of this period is 560 years, consisting of 490 Forgiveness years plus 70 unreckoned years! In His RC God does not count the 70 years when His people were under judgement.
There are 411 years from the 15th Solomon to the start of the Babylonian Captivity (see the Chart at the end). The 70 years Captivity in Babylon are well known in recorded history to be 607 BC-537 BC (the Cyrus Decree), as is the Ezra Decree in the 7th Artaxerxes (Ezra 7) at 458 BC, which is the end of the Great Jubilee Cycle and the start of the next one (Daniel’s 70 Weeks). This tells us that the final portion of this Cycle is 79 years. Adding up all the years (411+70+79) gives 560 years -70 unreckoned = 490 years!
*Make an initial attempt by using this Worksheet
Now the Chart for this Time-Period (below) shows the Chronology of Judah which is mostly straightforward, but due to some special situations there are some entries that are not immediately obvious. To get the right answers one has to put together all the relevant information from the reigns of both the kings of Judah' and Israel, comparing their two chronologies alongside each other. This belongs to a more advanced study where we have to use the wealth of data given in the Bible to deduce how both Israel and Judah measured their reigns, and then systematically put the information together to give the complete picture of both Kingdoms. The result of this detailed study is shown in the Chart below, where all the numbers have already been filled in.
To see how this is done and to verify these conclusions go here to see a detailed Chart synchronising the Kingdoms of Judah and Israel. (CHART in PREPARATION)