In 2 Chronicles 33, the author records the capture of Manasseh by the Assyrians, his subsequent imprisonment, and then his repentance and return to Jerusalem. None of this material is recorded in the parallel account of Manasseh in 2 Kings 21. Why might this be the case and, secondly, is the account in 2 Chronicles historically plausible? Norman Geisler and Thomas Howe tackle the first question in When Critics Ask : A Popular Handbook on Bible Difficulties:

Apparently the author of 2 Kings did not record the repentance of Manasseh because of the lack of influence it had upon the steady decline of the nation. The Book of 2 Kings concentrates primarily upon the actions of the covenant people of God as a whole. The repentance and reforms of Manasseh did relatively little to turn the nation around from its path to judgment, while his sinful leadership early in his reign did much more damage to the nation. Even in the 2 Chronicles passage we find this statement: ‘Nevertheless the people still sacrificed on the high places, but only to the Lord their God’ (2 Chron. 33:17). Even though the people dedicated their sacrifices to the Lord, they were still committing sin, because sacrifices were to be made at the temple, not upon high places which were originally altars to false gods. Despite the efforts of Manasseh, the people would not totally dedicate themselves to the Lord.

Is the account of Manasseh being taken by the Assyrians plausible historically? J. A. Thompson, in vol. 9, 1, 2 Chronicles, The New American Commentary, attempts to answer this question for us.

A historical question has been raised in regard to Manasseh’s captivity in Babylon, taken there by Assyrian forces, since there is no extrabiblical documentation for these events. This fact is not, of course, a sufficient reason for rejecting their historicity. Assyrian records are by no means sufficiently comprehensive to allow any argument from silence to decide the issue. There is valuable circumstantial evidence which has persuaded a good number of scholars that historical events underlie the Chronicler’s narrative. The Assyrian records mention Manasseh. He is listed among twenty-two kings of Hatti, the seashore, and the islands, who were summoned to Nineveh by Esarhaddon (650–669 B.C.) to bring building materials for a new palace. Asshur- banipal (668–627 B.C.) mentions him among vassal kings who participated in a campaign against Egypt.

In these references Manasseh appears as submissive to the Assyrian king. The question is asked regarding what historical circumstances would have brought about his humiliation and punishment by Assyria. Various proposals have been made. Manasseh quite possibly may have been on the side of Shamash-shum-ukin, who revolted against his brother Asshur-banipal. The inscriptions of both Esarhaddon and Asshur-banipal abound in references to Egypt and the Palestinian states in the time of Manasseh, who reigned for fifty-five years.

One other important Assyrian source is the vassal-treaties of Esarhaddon dated in the year 672 B.C. The crown prince of Assyria, Asshur-banipal, was inducted at a special ceremony where representatives of all the lands under Assyrian control were present. These representatives were sworn not to arouse the anger of the gods and goddesses against him and to serve Ashur as their god. They were bound by fearful oaths to support the crown prince after the death of his father. These treaties are not entirely intact, and the name of Manasseh does not appear. But the interest and activity of both Esarhaddon and Asshur-banipal in the west may well have forced compliance with their demands on Judah. Naturally vassals took opportunity to deviate from the treaty obligations laid upon them and even to rebel. In fact, numerous rebellions are attested in the reigns of Esarhaddon and Asshur-banipal.

By all accounts, the Chronicler’s narrative is historically reliable, but it of course includes a theological wording.