וַֽיְהִי֙ בִּשְׁנַ֣ת שָׁלֹ֔שׁ לְהוֹשֵׁ֥עַ בֶּן־אֵלָ֖ה מֶ֣לֶךְ יִשְׂרָאֵ֑ל מָלַ֛ךְ חִזְקִיָּ֥ה בֶן־אָחָ֖ז מֶ֥לֶךְ יְהוּדָֽה׃
Now it came to pass in the third year of Hoshea son of Elah king of Israel, that Hezekiah the son of Ahaz king of Judah began to reign.
Read midrashic interpretation of II Kings 18:1: and classical rabbinic exegesis.