Glyph and Origin

The glyph is a simple pair of curved strokes read as a ram's horns, though an older competing reading takes the same two arcs as eyebrows above the bridge of a nose, matching the traditional medical doctrine that Aries governs the head; neither account is documented in an ancient source, and the derivation remains a matter of inference rather than proof.

The uniform twelve-sign zodiac was defined in Babylonia in the mid-first millennium BCE and fixed as a set of equal thirty-degree signs in Hellenistic astrology. The written mark itself is first securely attested centuries later in the Byzantine copies of Greek horoscopes; a widely cited early witness to that manuscript culture is Vaticanus graecus 1291, an astronomical codex generally dated to around 813 to 820, prized more for its painted zodiac figures, drawn in white against a night-blue ground, than for the small abbreviated glyphs used in its tables. The forms were regularised again in the fifteenth century as printed almanacs began fixing zodiac notation in type, most famously Regiomontanus's Kalendarium and Ephemerides, produced from his own Nuremberg press starting in 1474 and among the first books to print astronomical diagrams and tables at all. Because the tropical signs are measured from the moving equinox, Aries the sign no longer coincides with the constellation Aries, a drift caused by the slow precession of the equinoxes.