(γενέθλια, birth), a name given by the ancients to those who pretended to foretell what should befall a man by means of the stars which presided at his nativity. They were also called Chaldei or Babylonii, from the country where their science was first developed; sometimes astronomi, astrologi, or planetarii, because they observed the stars; and likewise mathematici, from their employing diagrams such as were used by geometers. Edicts at various times were issued against the astrologers of ancient Rome; yet notwithstanding the rigour of the penal enactments by which they were denounced, they continued to maintain their popularity, and were never altogether expelled from the city. Hence Tacitus speaks of them as "genus hominum quod in civitate nostra et vetabitur semper et retenetur."