early 13c., from Anglo-French escorge, back-formation from Old French escorgier "to whip," from Vulgar Latin *excorrigiare, from Latin ex- "out, off" + corrigia "thong, shoelace," in this case "whip," probably from a Gaulish word related to Old Irish cuimrech "fetter." Scourge of God, title given by later generations to Attila the Hun (406-453 C.E.), is attested from late 14c., from Latin flagellum Dei.
c.1300, "to whip," from Old French escorgiier and from scourge (n.). Meaning "to afflict" (often for the sake of punishment or purification) is from late 14c. Related: Scourged; scourging.