ALKE was the female personification of battle-strength, prowess and courage. She was one of the spirits of the aigis, the tasselled arm-guard of Zeus. The others were Eris (Strife), Phobos (Terror) and Ioke (Onslaught).
She was probably one of the battle-spirits known as Makhai.
Perhaps a daughter of ERIS, though nowhere stated
Homer, Iliad 5. 738 ff (trans. Lattimore) (Greek epic C8th B.C.) :
"Across her [Athena's] shoulders she threw the betasselled, terrible aigis (aegis), all about which Phobos (Terror) hangs like a garland, and Eris (Hatred) is there, and Alke (Battle Strength), and heart-freezing Ioke (Onslaught) and thereon is set the head of the grim gigantic Gorgo (Gorgon), a thing of fear and horror, portent of Zeus of the aigis."
[N.B. The daimones (spirits) imbued the aigis with its power.]
- Homer, The Iliad - Greek Epic C8th B.C.