“In those days there was no king in Israel.” This statement occurs in Judges 17:6, 18:1, 19:1, and 21:25, thus it appears near the beginning and also the very last sentence of Judges, thus setting apart the last five chapters from the rest of Judges (see commentary on Judg. 17:6).
“their inheritance had not fallen to them.” Joshua had given the Danites an inheritance, but they could not manage to dispossess the Amorite population from their territory. Instead of doing what it took to take their territory from the native Canaanite population, they left the area and went north and conquered Laish. There were, however, some cities in the area Joshua assigned to Dan that continued to be inhabited by Danites. Zorah, where Samson was from, was one of those cities, and Samson was a Danite. More about Dan is in Joshua 19:40-48 and Judges 1:34. So the inheritance had “fallen” to them in the sense the Danites had been given it, but it had not “fallen” to them in the sense that they had conquered and controlled it.