Lot was Abraham's nephew and Isaac's cousin. God destroyed Sodom, Gomorrah, and other nearby cities. Then Lot and his two unmarried daughters took shelter in a cave east of the Dead Sea (see Genesis 19:30–38). Lot's daughters got their father so drunk that he had sexual relations with them.
Their children became the nations of Moab and Ammon. Because they were relatives of Israel, they would not disturb the Moabites. King David's great-grandmother Ruth was from Moab (Ruth 1:4). David sent his family to Moab for safety when Saul chased him (1 Samuel 22:3–5).
Ar was probably the capital of Moab.