Glyph and Origin

The glyph shows a circle surmounted by a rising crescent, conventionally read as the bull's head and horns, though like most of the pictorial readings of the zodiac signs this is a traditional gloss rather than an explanation attested in any ancient source. The sign belongs to the Babylonian twelvefold zodiac transmitted through the Hellenistic Greek world, and the myth of Zeus carrying Europa across the sea in bull form was later attached to the same stars.

The written mark survives mainly through the medieval Byzantine copying of Greek horoscopes, the manuscript culture catalogued by Otto Neugebauer and Henry Van Hoesen in Greek Horoscopes, and it was fixed into a stable printed form only with the astronomical almanacs and ephemerides of the fifteenth and sixteenth centuries. Among the earliest and most influential of these was the Kalendarium of Johannes Regiomontanus, printed at his own Nuremberg press from 1474 and notable for pioneering the printing of astronomical diagrams alongside numerical tables. Through precession the tropical sign has since separated from the like named constellation, so the Sun no longer occupies the constellation Taurus while the calendar still marks the sign of that name.