“But he rebelled against him in sending his ambassadors into Egypt, that they might give him horses and much people.”
This verse hides a huge amount of intrigue between Jerusalem and Egypt. Who made the first contact we do not know, probably Egypt, seeking to foment trouble among the smaller states for their own benefit, and seeking assistance in their own plans against Assyria. But Zedekiah, saw his chance to break for freedom and ‘rebelled against the king of Babylon' (2 Kings 24:20). This was contrary to Yahweh's words through Jeremiah (Jeremiah 27:12-15). He sent to Egypt for assistance in the form of soldiers and horses.
We have independent confirmation of such intrigues in the Lachish letters, a collection of twenty one ostraca found in the ruins of Lachish. ‘Konyahu, the son of Elnathan, commander of the army, has gone down on his way to Egypt'.