Mediterranean Archaeology and Archaeometry, Vol. 11, No. 1, pp. 59‐68 Copyright © 2011 MAA Printed in Greece. All rights reserved. THE EVIDENCE FROM KNOSSOS ON THE MINOAN CALENDAR G. Henriksson1 and M. Blomberg2 1 Formerly Department of Astronomy and Space Physics, Uppsala University, retired Mailing address: St. Olofsgatan 10A ög, SE‐75312 Uppsala, Sweden 2Formerly Department of Archaeology and Ancient History, Uppsala University, retired Mailing address: Norrtullsgatan 31, SE‐11327 Stockholm, Sweden. Received: 30/07/2010 Accepted: 18/10/2010 Corresponding author: [email protected] ABSTRACT From the early results of our archaeoastronomical investigations at the peak sanctuaries on Petsophas and Mt Juktas, we inferred that the Minoans had a lunisolar calendar that began at a par‐ ticular phase of the moon on or following the autumn equinox. We used classical archaeoastronomical methods: a digital theodolite with observations of the sun to determine the orientation of the coordinate system, measuring the orientations of foundations to celestial bodies, and determining the positions of celestial bodies at the appropriate times in the past using our own programs. In our later investigation of the palace at Knossos, we found further evidence including the impressive use of a reflection in the central palace sanctuary to determine the beginning of the Minoan year and for knowing when to intercalate a lunar (synodic) month in the lunisolar calendar. The reflection occurred at the precise moment of sunrise at the equinoxes and also during the eleven days before the spring equinox and after the autumn equinox. We also discovered that the non‐integral length of the solar year would have been revealed by the unique shift of the reflection during a series of four years. Later results at three other Minoan sites underscored the probability that the Minoans had a solar calendar and twelve solar months. KEYWORDS: Archaeoastronomy, double axe, Minoan astronomy, lunisolar year, Orion, solar year 60 G. HENRIKSSON & M. BLOMBERG INTRODUCTION tions of the stars, was underway in these cul‐ tures by the Early Bronze Age (Wachsmann In our archaeoastronomical investigation of 1998). the peak sanctuaries on Petsophas (Henriksson It is unfortunate that such records have not and Blomberg 1996, Blomberg and Henriksson survived from Crete, but we can assume a simi‐ 1996, Blomberg 2006) and Mt Juktas (Blomberg, lar interest there. There are star‐like decorative Henriksson and Papathanassiou 2002), we objects on many seals, which, however, are not found good evidence for a lunisolar calendar differentiated as to star, sun, moon or planet that began in connection with the autumn equi‐ (Goodison 1989). There are also sailing boats on nox. Here we present evidence found at the seals from the Early Bronze Age, giving evi‐ palace at Knossos showing that a reflection dence that Minoans were navigating in the could be used to mark the morning of the Mediterranean by that time (Betts 1973; Blom‐ equinoxes and also the eleventh morning after berg and Henriksson 1999). Another source of the autumn equinox. It seems also possible that information about Minoan astronomy is our the reflection could have been used to regulate discovery that the Minoans were making exact a solar calendar based on the tropical year of orientations of important buildings to major the sun, i.e., from one autumn equinox to the celestial events, such as sunrise and sunset at other. This evidence supports our findings from the equinoxes and solstices, from the beginning Petsophas and Mt Juktas and, in addition, may of the Middle Bronze Age (ca 2000 BCE). Thus it indicate that the Minoans had a solar calendar is likely that they had considerable knowledge with 365 days and that every fourth year they of the motions of the celestial bodies much ear‐ added one day to keep the beginning of solar lier. years at the autumn equinox. The debated dates of the Greek constellations The palace is of central importance for the arising from descriptions in Aratos not being of discovery of such evidence. It was by far the his time has indicated to us that he was, in part, largest and grandest building in the island and following a very long tradition dating from as had deep influence on Minoan culture. It was long ago as 2000 BCE, and that changes were inhabited for hundreds of years, but despite made as the changed position of important stars many alterations due to a number of destruc‐ due to precession compromised their use in a tions and reconstructions, in addition to the calendar and for navigation (Henriksson and usual repair and renovation required by long Blomberg 2002). It has been assumed that there usage, the evidence could be discovered due to was a Minoan tradition passed down by the the careful excavations and publications now Mycenaeans. We may have here an argument for available to us from over a century of study. An a derivation of some of the Greek constellations entry into the vast literature on the site can be from Minoan predecessors. Aratos’s descriptions found in the Festschrift dedicated to Sinclair give us some idea of the stars in some of the con‐ Hood, director of the excavations for many stellations, but not the earlier names of those years (Evely, Hughes‐Brock and Momigliano constellations. The lack of Minoan written re‐ 1994), and in the volumes of the Annual of the cords or art with recognizable astronomical con‐ British School at Athens from 1900 and after‐ tent makes it difficult to find any support in this wards. important question. The development of lunisolar and solar cal‐ endars implies a long history of systematic ob‐ servations of the motions of the celestial bodies. ARCHAEOLOGICAL SUMMARY We can see from the written records of Mesopo‐ The old palace was constructed above a set‐ tamia and Egypt that astronomy had an impor‐ tlement that had been inhabited continuously tant role in those cultures by the early Bronze from the second half of the 8th millennium BCE Age (3rd millennium BCE). They had calendars (J.D. Evans 1994). The part of the west wing (Cohen 1993; Clagett 1995), and navigation, where the temple repositories and the pillar with its dependence on knowledge of the posi‐ crypts were found is known as the central pal‐ THE EVIDENCE FROM KNOSSOS ON THE MINOAN CALENDAR 61 ace sanctuary and may well have been the most When first excavated, there was a corridor important religious area of the building (Fig. 1). south of the pillar crypts and a door in the southwest corner leading to the famous storage rooms to the west. The corridor is known as the corridor of the house tablets because of the house‐like sign on the Linear B tablets found in it. A conspicuous but much worn alabaster con‐ cave stone lies near the door (Fig. 2). Fig. 1. Plan of the palace at Knossos (Myers, Myers and Cadogan 1992, with permission). Fig. 2. The central palace sanctuary as excavated (Hood and Taylor 1981, with permission). Quite naturally, the sanctuary became a fo‐ All of the other paving stones are flat, but cus for our attention. Its excavation history has the edges of this stone rise a few centimetres been thoroughly analysed by Marina Panagio‐ above the floor level to form a bowl (Fig. 3). taki (1999). Below the west wing there had ex‐ isted a previous “palace” with the same orienta‐ tion, built in the Early Minoan III period (2200‐ 2000 BCE).1 Most traces if this early building seem to have been removed when the Old Pal‐ ace was built in MMIB (1910‐1875 BCE) (Catling 1973‐1974; Shaw 1977). The evidence of the vat room deposits indicates a destruction of the shrine in MMIB. All other test pits underneath the floors of the shrine seem to rest immediately Fig. 3. The concave stone in the corridor of the house on top of Neolithic or EMI‐II deposits. The ab‐ tablets. Photo Göran Henriksson 1996. solute chronology of this part of the Bronze Age in Crete is much disputed, but we accept the Preliminary measurements in 1992 using a dating proposed by Manning, with the MMIB magnetic compass and estimating the altitude period ending about 1875 BCE (1995:217). The of the Ailias Ridge opposite indicated to us that area was changed, for example by the Mycena‐ there might have been an orientation to sunrise eans, who were in control of the island from at the equinoxes from the bowl. This suggested about 1450 BCE, but the orientation of the the use of the bowl filled with liquid to reflect original area of the central palace sanctuary the rays of the sun, as it was known to ancient seems not to have been changed (Driessen and astronomers that looking directly at the sun was Macdonald 1997). dangerous to eyesight (Plato 1914: 343 (99D)). The reconstruction of the sanctuary as it was originally is the result of a careful archaeologi‐ 1 We are grateful to Sinclair Hood for showing us a cal study made in the 1980’s (Driessen 1990). remaining wall from this building. 62 G. HENRIKSSON & M. BLOMBERG The corridor of the house tablets did not exist stretches north‐south with an even horizon for from the beginning; the area was then an inte‐ some hundred meters opposite the southern gral part of the sanctuary (Fig. 4). door of the sanctuary (Fig. 5). Fig. 4. Reconstruction of the original central palace sanctuary (Driessen 1990, with permission). There was no door in the southwestern cor‐ ner, as a double axe inscribed in the wall near the floor was partially destroyed when the door was cut through (Fig. 8).