Moreover the children of Ammon passed over Jordan to fight also against Judah, and against Benjamin, and against the house of Ephraim; so that Israel was sore distressed. (Judges 10:9)
Emboldened by their victories over the tribes in Gilead, the Ammonites crossed the Jordan River and began raiding all central Palestine where the tribes of Judah, Benjamin, and Ephraim dwelt.