Sefer Melachim II takes place in Iron Age II, a period of tremendous geopolitical upheaval and change in the region. It is an era called “the era of mass deportations” and one which can be termed “the Age of Empires”. The main shift is from regional kingdoms or city states, which are local, powerful players, to Empires, which are administrative innovations which enable a largest territorial dominion the world has ever seen. Beyond the power of Egypt, Assyria became the iron fist which terrorized and held together the Near East.
Assyria was responsible for the mass-deportations which destroyed nations and ethnicities, deliberately mixing them up to prevent future rebellions. Check out TED Ed video for elaboration: The rise and fall of the Assyrian Empire https://youtu.be/7pa54hWROpQ.
The wrath of Assyria has destroyed the 10 Tribes - the entire Kingdom of Israel - which is now gone.
With the decline of Assyria who over-extended themselves, there is a power vacuum, in which King Yoshiyahu is able to gain some power, which he quickly loses when meddling with foreign affairs - attempting to block Pharaoh Necho II at Megiddo - on his way to the Battle of Carchemish (605 BCE). https://en.wikipedia.org/wiki/Battle_of_Carchemish
Babylon wins this battle, and is now the new world power. Babylon eventually destroys the Kingdom of Yehuda and exiles them to Babylon, in two shifts, leaving Gedaliyahu ben Ahikam as governor - who is hastily killed. But there is a relatively happy ending to this Exile, as we prosper in Babylon, and eventually return to rebuild the Temple.
Archaeology Snapshot is a discussion on the location, timeline, main characters and highlights from history and archaeology, for each Sefer in Tanach.