PURPLE, a colour-name, now given to a shade varying between crimson and violet. Formerly it was used, as the origin of the name shows, of the deep crimson colour called in Latin purpura, purpureus and in Greek Trop<j>iipa, fop^vptm (from irop<t>vpti.v, to grow dark, especially used of the sea). This was properly the name of the shellfish (Purpura, Murex) which yielded the famous Tyrian dye, the particular mark of the dress of emperors, kings, chief magistrates and other dignitaries, whence " the purple " still signifies the rank of emperors or kings.
The title of porphyrogenitus (Gr. vofxjivpoyiivriTot) was borne particularly by Constantine VII., Byzantine emperor, but was also used generally of those born of the Byzantine imperial family. This title, generally translated " born in the purple," either refers to the purple robes in which the imperial children were wrapped at birth, or to a chamber or part of the imperial palace, called the Porphyra (ir6p<f>vpa), where the births took place. Whether this Porphyra signified a chamber with purple hangings or lined with porphyry is not known (see Selden, Titles of Honour, ed. 1672, p. 60 seq.).