During Isaiah’s ministry, Jerusalem’s population was greatly reduced. War, famine (lack of food), and disease caused many deaths (Isaiah 3:1–3; 6:13; 14:30; 22:2; 37:4).
So many men died that few were left in the city. This created a serious absence of leadership (see Isaiah 3:1–12). Without strong leaders, the city became weak and unstable.
Even worse conditions were coming. In 734–732 BC, Judah faced war with an alliance(a military agreement) between Syria and Israel (2 Chronicles 28). Later, from 605 to 586 BC, Babylon conquered Judah. Jerusalem was destroyed and fell to its enemies.