from the time when first the son of Atreus, lord of men, and godlike Achilles stood apart in strife.

Two verbs in the dual, a form Greek keeps for exactly two: diastētēn erisante, “the two of them parted, having quarreled.” The grammar makes the pair a pair at the very moment they split. “From the time when” is ambiguous on purpose or by accident. It can tell the Muse where to start singing, or say how long the will of Zeus had been working. Either way the epic does not begin with the war, nine years old by now, but with one quarrel. Each man arrives with his formula: Agamemnon is “lord of men,” the commander; Achilles is “godlike,” dios, a word from the same root as Zeus.