A specific list of foreign nations and territories remained unconquered within the borders of the land. God intentionally left these groups in place to serve as both a spiritual and military test for the Israelites. This situation forms the historical backdrop for the turbulent era of the Judges, detailing exactly which nations were left behind for this purpose [רש״י, מצודת דוד].
The account begins with the five lords of the Philistines. While their title indicates power and authority [מצודת ציון, ביאור שטיינזלץ], the primary approach among commentators is that this refers not just to the leaders, but to the actual regions under their control. These are the five major Philistine cities (Ashdod, Gaza, Gath, Ashkelon, and Ekron) along with their surrounding villages [רלב״ג, רד״ק, אברבנאל]. This presents an apparent contradiction, as earlier records indicate that the tribe of Judah had already captured Gaza, Ashkelon, and Ekron. The commentators agree that following Judah's initial conquest, the Philistines returned and reclaimed these cities, and the Israelites were unable to drive them out a second time [מצודת דוד, רלב״ג, רד״ק, אברבנאל]. Furthermore, this unconquered territory also includes certain regions and valleys where the Philistines lived that the Israelites had never managed to capture in the first place, forcing them into ongoing warfare [רלב״ג, רד״ק, מלבי״ם].
The focus then shifts to the northern nations, specifically the Canaanites, Sidonians, and Hivites. These foreign tribes lived in the areas surrounding Tyre and Sidon, situated in lands that were originally intended to be part of the Israelite inheritance [ביאור שטיינזלץ]. Their geographic location is defined as spanning Mount Lebanon, from Mount Baal Hermon up to the road leading to the city of Hamath [מצודת דוד]. Ultimately, this detailed mapping serves as a general introduction to all the upcoming stories of the Judges. It exposes the root of the unfolding crisis: living among these foreign nations eventually led the Israelites to intermarriage and idol worship. This destructive process brought great trouble upon them, ultimately requiring the rise of the saving Judges [אברבנאל].