Originally both books of kings formed only one book, compare the final Masora ( 2 Kings 25,30 EU ).
The division of the books according to 1 Kings 22.54 EU - in the middle of the history of Ahaziah of Israel - is objectively not justified. The division into two books comes from the tradition of the Septuagint, where it was probably due to the manageable length of a scroll - Greek texts take up much more space than Hebrew due to the structure of the Greek language (long words) and script (many vowels) Texts (short words, no vowels) with the same content. It was handed down in the Vulgate and was incorporated back into the Hebrew Bible in the late Middle Ages.
The second book of kings continues the story of the separate kingdoms of Israel and Judah (Israelite division of the empire 926 BC) up to the fall of Samaria in 2 Kings 17. This is followed by the story of Judah up to the fall of Jerusalem and the later pardon of Jehoiachin.
The line connecting Hezekiah to David (v. 3) is surprising in that Hezekiah's good deeds are compared to David, who is said to have done "what is right," which is in tension with the other depictions of David who also know about his sins.
Classically, Hezekiah's good deeds include the destruction of high-altitude sanctuaries, mazebas and the Asherah (singular: Codex Leningradensis, alternatively also plural: Asheres). Atypical, however, is the mention of the dismemberment of the bronze serpent that Moses had made. Overall, it is not about the question of monotheism, because all of the elements mentioned can have references to Adonai. It is more about a religious policy that opposes images and worship in different places ("heights").
The theological interpretation of the deportation of the northern kingdom is that it was due to the sins - namely that they did not listen to God and broke the covenant (v.12).
Hebraistically valuable is the statement in v. 26 that there is apparently a dialect language that can be distinguished from Hebrew, which is called "Yehudit" (יְהוּדִית), thus probably a dialect specific to the southern empire, which according to the text also the 2nd highest man Assur (Rabschake) can speak.