Jehoahaz, whose other name was Shallum, was the middle of Josiah's three sons all of whom ruled Judah after Josiah. Jehoahaz was the people's choice (v. 31), but he reigned for only three months in 609 B.C.
When Pharaoh Neco defeated Josiah at Megiddo (v. 29) Judah fell under Egyptian control. Neco summoned Josiah's successor Jehoahaz to meet him at Riblah. This town stood about 65 miles north of Damascus in central Aramea. The meeting took place before the battle of Carchemish. Neco found Jehoahaz obstinate, as his father had been, so he imprisoned him and sent him back to Egypt (v. 34) where he died later (Jer. 22:10-12). Neco also imposed a heavy tax on Judah (v. 33) and installed Jehoahaz's older brother Eliakim (Jehoiakim) on Judah's throne as his puppet. The naming of a person shows superiority over that person. Neco was declaring his sovereignty over Judah's king by renaming him Eliakim.