A Hellenistic astrologer's board from Croatia

In a paper just published in the Journal for the History of Astronomy, Stašo Forenbaher (Institute for Anthropological Research, Zagreb) and Alexander Jones (ISAW) announce the discovery of ivory fragments of a Hellenistic astrologer's board in a part of a cave in southern Croatia that was sealed off towards the end of the first century BCE after having served as a cultic sanctuary. The board, which an astrologer would have used to display to his client the arrangement of heavenly bodies in a horoscope, is the oldest such object known to exist. It witnesses the rapid spread of Greek horoscopic astrology, which came into existence as a fusion of Mesopotamian and Egyptian astral divination with Greek cosmology probably not long before 100 BCE.

Nakovana Cave overlooks the Adriatic Sea from a ridge near the western tip of Pelješac Peninsula, 100 kilometers northwest of Dubrovnik. Some of the most important Adriatic sea-lines of antiquity pass through the channels below the cave. The Nakovana Project (directed by Timothy Kaiser and Stašo Forenbaher) began work at the cave in 1999, and towards the end of the field season a hitherto unknown extension of the cave was discovered. Fragments of pottery vessels were lying about, most of them Hellenistic finewares datable to the last four centuries BCE, evidently the accumulated remains from cult offerings. The ivory fragments were discovered among this material.

When complete, the board had twelve arc-shaped ivory plates forming a complete circle and representing the twelve signs of the zodiac. An astrologer would have displayed a horoscope by placing colored stones standing for the Sun, Moon, and planets in the places they occupied in the zodiac on a particular date, for example a client's birthdate. It is not clear whether the board was actually used where its remains were found in Nakovana cave or whether it was deposited there as a precious offering.