Judges 1:9

And afterward the children of Judah went down to fight against the Canaanites, that dwelt in the mountain, and in the south, and in the valley.

Cross-reference

Joshua 15:13-20 details Caleb's conquest of Hebron and Debir, providing the background for the events in Judges 1.

Joshua 10:36 describes Joshua's conquest of Hebron in the hill country, paralleling the Judahite campaign in Judges 1:9.

Joshua 11:21 recounts Joshua's defeat of the Anakim in the hill country, which the Judahites later engaged.