Jeconiah was the son of King Josiah. Unfortunately he would end up being nothing like his father. Instead he would fall back to the old ways. He was imprisoned by Pharaoh Neco and later made King by him. He taxed people and basically was a puppet.
He even changed his name to Jehoiakim because that was what Pharaoh Neco wanted. This however would not last. King Nebuchadnezzar had an eye on Israel, and he would take it and Israel would be in captivity for a very long time afterwords.