Judges 6:33
Then all the Midianites and the Amalekites and the children of the east were gathered together, and went over, and pitched in the valley of Jezreel. Then all the Midianites and the Amalekites and the children of the east were gathered together, and went over, and pitched in the valley of Jezreel.
The host that assembled in the valley was made up of Midian from the eastern border and Amalek from the southern desert, coming together in great numbers. Their incursions spread through the land, eating up the harvest and forcing the inhabitants to abandon open settlements for refuge in towns, fortresses, and caves.
This gathering belongs to the oft-repeated history in which Israel's backsliding into idolatry was punished by oppression from enemies, followed by confession and deliverance. In this instance the affliction came because of Israel's sin and the withdrawal of divine protection, and it continued seven years until distress drove the people to confess their wrong before a deliverer was raised up. That deliverer was a faithful and valiant man appointed to overthrow idolatry and free Israel from its foes, yet after his death the people gradually drifted back to their idols.
The massing of the enemy formed the setting for Gideon's call to deliver Israel, for after he took his stand against Baal worship he blew the trumpet of war and men rallied to his standard. His own tribe answered, together with Asher and Zebulun and Naphtali.