What does Isaiah 7:1 mean?

During the time when Ahaz, son of Jotham and grandson of Uzziah, was king of Judah, King Rezin of Aram and King Pekah of Israel marched up to attack Jerusalem, but they couldn’t take it. Isaiah 7:1 - Modern Text Bible

(Two neighboring kings try to conquer Jerusalem, but they fail. This sets the stage for God’s message to Ahaz.)