Previously the Horites lived in Seir, but the descendants of Esau took over their land. They killed the Horites and settled there, just like Israel did when they occupied the land that the Lord had given them.)
This was when they were in the valley to the east of the Jordan near Beth-peor in the country of Sihon king of the Amorites. He had ruled from Heshbon and had been defeated by Moses and the Israelites after they had left Egypt.
They took over his country and the country of Og king of Bashan. (They were the two kings of the Amorites who previously ruled on the east side of the Jordan.)
as well as all the land of the kingdom of Og of Bashan, who had ruled in Ashtaroth and Edrei. He was one of the last of the Rephaites. Moses had defeated them and driven them out.