Who was Amalek?
In the Hebrew Bible or Christian Old Testament, Amalek was the son of Eliphaz, by his concubine Timnah, of the Horites; grandson of Esau; duke of Edom (Gen. 36:12,16).
The Edomites seized the Horite territory.
In Hezekiah's reign the last remnant of Amalek in Edom was dispersed by the Simeonites (1 Chr. 4:42,43).
IBSE, (in the public domain) with minor edits.