To chronicle Israel’s deepening moral degradation after the death of Joshua, marked by a downward spiral of disobedience, which in turn brought God’s judgment through military subjugation by other nations, which in turn brought Israel to repentance, to which God responded by sending civil or military judges to provide deliverance—until the next descent into disobedience. By the end of the book the tribes of Israel are splintered and live as a law unto themselves.