The country of Moab is on the east side of the Dead Sea, between Edom and Ammon. The origin of the Moabites came from the incestuous union of Lot with his eldest daughter, who bore him a son named Moab (Genesis 19:30-38).
The first appearance of the name Moab is found inscribed in front of the temple Luxor, 13th century BC. Moses was buried in Moab.
When Israel settled in the new land, the tribes of Reuben and Gad conquered parts of the country of the Amorites that had formerly belonged to Moab. There was constant fighting between Israel and Moab. Saul and David both fought there, and Ehud, one of the Judges, subdued Moab for 80 years (Judges 3:26-30).
But the two countries were also friendly to each other at times, as in the Book of Ruth. Ruth a Moabitess was the great-grandmother of King David. Moab freed itself from Israel's domination after King Ahab's death.
Sargon II speaks in his annals of the conquest of Moab and of the Moabite soldiers who later helped the Assyrians in their wars against the Arabs. Moab plundered Judah after it was defeated by Babylon, and later became part of the Babylon and Persian empires.
Many prophets condemned Moab for scoffing and boasting against Israel, and for their pride, arrogance, insolence and worshiping idols.
Today the country known as Moab does not exist, the area that was Moab during Biblical times is now part of Jordan.