Amos 1:8

1:8 Ashdod. A strong and prosperous Philistine city, located eighteen miles northeast of Gaza.

Ashkelon. This third royal city lay halfway between Gaza and Ashdod on the Mediterranean coast.

Ekron. The precise location of this Philistine royal city is uncertain; a number of sites northeast of Ashdod have been suggested. Gath, the fifth royal city, is not mentioned because it had already been defeated by Hazael (2 Kin. 12:17), and again by Sargon II (722–705 b.c.). Assyria was the primary instrument of judgment against all these cities, and all four are subsequently mentioned in Assyrian annals as vassals of Esarhaddon (681–669) and Ashurbanipal (668–627).