The country of Moab was situated east of the Dead Sea. The Moabites were descendants of Lot (Abraham's nephew) and his eldest daughter (Genesis 19:31–37) and were therefore related to the Israelites. The two nations were often at odds with each other. Eglon, the king of Moab, attacked Israel, and Israel was subject to Moab for the next eighteen years until God sent Ehud to deliver them (Judges 3:12–30).
In 2 Samuel 8:2, we can read how David later conquered the Moabites and subjected them to the Israelites. 2 Kings 3:1–27 contains the history of Moab’s rebellion against Israel.
The Moabites worshipped the god Chemosh (Jeremiah 48:46).
1 An oracle concerning Moab. Because Ar of Moab is laid waste in a night, Moab is undone; because Kir of Moab is laid waste in a night, Moab is undone.