The hand of Midian prevailed against Israel; and because of Midian the children of Israel made them the dens which are in the mountains, and the caves, and the strongholds.
The Amalekites and other tribes that lived in the Arabian Desert east of Canaan joined the Midianites in their raids. These desert-dwellers were the "sons of the east" (Judges 6:3). The raids extended all the way to Gaza on the Mediterranean coast (Judges 6:4), far into Israel.