The day an island was shattered

The eruption of Thera

The modern island of Thera is actually the rim of an old volcano. This volcano had erupted during the Bronze Age. What effect did this massive eruption have in the Aegean, and on nearby Crete in particular?

Josho Brouwers

Anyone who has been to Thera, also known as Santorini, cannot help but be struck by the fact that the island today is clearly the rim of an old volcano. In the centre of the flooded caldera lies the small, uninhabited island of Nea Kameni, which only emerged from the sea in the first century AD; the volcano is dormant, not inert.

The single largest eruption of Thera ocurred during the Bronze Age. A user on Reddit’s AskHistorians wondered what someone living in Bronze Age Crete would have experienced when the volcano at the heart of the island of Thera, located about 118 km north, erupted. They asked what Cretans of that time would have made of the eruption, and if their lives would have been affected.

In order to answer this question, we need to understand a few different things. First of all, we need to get an idea of the eruption, especially its scale. Secondly, we need to understand when the volcano erupted. Finally, we can examine what impact the eruption may have had on people back then.

The eruption of Thera

Sturt Manning goes into great detail with regards to this eruption in chapter 34 of Eric Cline’s Oxford Handbook to the Bronze Age Aegean (2010), pp. 457-474. He notes (p. 457):

The prehistoric ‘Pompeii’ of the Aegean world is the horizon of time sealed by the great eruption of the Thera/Santorini volcano in the Aegean in the mid-second millennium BC […]. This eruption entombed a thriving city with international links (referred to as Akrotiri, from the name of the nearby modern village) and other settlements on Thera, and, through the spread of a tephra blanket (airfall volcanic ash/debris), laid down a clear marker horizon across much of the southern and eastern Aegean, western Anatolia, and some of the East Mediterranean […].

Though known earlier, the site was excavated in the 1960s and is today a major tourist attraction. The eruption itself, as Manning puts it (p. 458):

was an epoch-scale event – one of the larger volcanic eruptions of the last several thousand years […] and it had a substantial, shorter-term impact on the region beyond Santorini, ranging from direct airfall tephra damage in the southeast Aegean, associated seismic and especially tsunami impacts, to (debated) effects on the environment and even the climate over the subsequent months to years […]

The concept of the “volcano” didn’t exist in historic times (cf. the eruption of Pompeii in AD 79) – there were mountains, and some of them might erupt violently. In Classical times, volcanos like Etna were said to house Hephaestus/Vulcanus’ workshop. Etna continues to be active to this day, unlike Vesuvius, which only smokes intermittently and rarely spews forth lava, or indeed Thera, which has been dormant for decades.

As to how life would have changed in the Aegean, there is considerable debate. The passage above from Manning makes clear that the effects of the eruption on the environment are debated. For example, was there less sunlight due to blockage from ash/clouds, and if so, did this lead to failed harvests? Neither do we fully understand the long-term effects it may have had on the immediate climate in the southern Aegean.

Still, it’s usually assumed that the eruption has some impact on Bronze Age Crete. Some have suggested – Manning gives references – that the eruption of Thera directly caused the downfall of the Minoan palaces on Crete, but this is no longer supported: the eruption occurred late during the ceramic phase known as Late Minoan IA, and the palaces on Crete weren’t destroyed until late in the following ceramic phase, Late Minoan IB.

The date of the eruption

How long passed between one event and the other is a matter of chronology. There is considerable debate regarding the date of the eruption: the conventional one, based on pottery and synchronisms with Egypt, suggests a date in the late sixteenth century.

However, radiocarbon dates suggest it happened in the later seventeenth century, ca. 1628 BC. (There are some competing radiocarbon dates; I’ll stick with this one for now.) The decision whether to accept the conventional date or the radiocarbon date, as Manning suggests in his chapter on chronology in Cline’s Handbook, has a lot to do with the age of the archaeologist in question: younger archaeologists tend to prefer the radiocarbon dates!

According to the “high” chronology, there’s approximately 150 years between the eruption and the destruction of the palaces (Late Minoan IB is dated ca. 1625/1600-1470/1460 BC). But even in the “low” chronology – that is, the conventional one, dated ca. 1500-1450 BC – there is some 50 years between the eruption of Thera/Santorini and the destruction of the palaces.

So whatever happened, the effects weren’t devastating enough to have an immediate impact on Bronze Age Crete in 1625/1525 BC or even 1600/1500 BC. Of course, absolute dates are a nightmare, which is why archaeologists prefer to stick to relative dates.

Regarding absolute dates for the Aegean Bronze Age, see the table in Cline’s handbook on p. 23, as well as my introductory article on Minoan Crete.

The impact of the eruption

The Thera eruption would have caused large tsunamis, which would have washed over the coastal areas of nearby islands, including Crete. But even then, the impact would have been relatively limited for Crete as a whole. A thin layer of ash and debris could also be cleaned up fairly quickly, as demonstrated by modern eruptions.

Yet, as Manning notes, some believe that even if the eruption didn’t have an immediate impact on Crete, it may still have been a contributing factor to the eventual destruction of all of the major Minoan centres at the end of the “Neopalatial” period, which marks the zenith of Minoan culture.

Our interpretation is made more difficult by the fact that we don’t know exactly what happened at the end of the Neopalatial age. John G. Younger, in an article on “Minoan women”, published in Stephanie Lynn Budin and Jean Macintosh Turfa (eds), Women in Antiquity. Real Women Across the Ancient World (2016), remarks (p. 588; my emphasis in italics):

At the end of LM IB, almost every Neopalatial site in Crete was destroyed by fire, with the exception of the central palace at Knossos […]. These destructions clearly marked a major societal change. The pottery that follows, LM II, is more formal and architectural rebuilding is rare. By the next period, LM IIIA1, Mycenaeans are in charge of Crete; they have established new megarons at a few sites (Ayia Triada, Gournia), and their scribes (native Minoans?) are writing documents in Greek (Linear B).

In this paper, Younger talks about the position of women in Minoan society, and that they clearly enjoyed considerable freedom and had a high status during the Protopalatial and Neopalatial periods of Minoan culture (i.e. the “Old” and “New” Palace periods).

This situation changed after the destructions, during the ceramic phase referred to as Late Minoan IB. Regarding this “societal change”, Younger writes (ibid.):

It is debated whether the destructions were the result of an internal rejection of the Knossian palatial system or whether Mycenaeans from outside played a role. Regardless, after these destructions, the status and roles of women changed: no more bench rooms, Lustral Basins, large-scale women in landscapes, or imported blue monkeys. Also gone are stone relief vessels, stone bull’s head rhyta, and ivory and faience figurines. In other words, after LM IB, all the products and propaganda that reflect the Neopalatial ideology of Knossos disappear.

The destructions are so widespread across Crete that they certainly suggest some form of societal collapse, rather than the actions of an invader who managed to wreak havoc on a scale otherwise – and to the best of my knowledge – not seen in the Bronze Age world.

One problem is that we don’t really know whether the “Minoans” and the “Mycenaeans” distinguished themselves from each other as different ethnic groups (the terms are archaeological labels, first and foremost). Furthermore, the “Mycenaeans” who formed the elite in Knossos and elsewhere after Late Minoan IB may have lived there well before that period, as resident foreigners, for all we know.

Closing remarks

The eruption of Thera was massive, and its effects are likely to have been felt across a large area. The island itself was shattered and must have cost the lives of untold numbers of people who lived on the island.

The absolute date of the eruption is a matter of some contention, but what is clear is that it did not have an immediate effect on the island of Crete, located to the south of Thera. Nevertheless, it cannot be excluded that the eruption played some part in the eventual downfall of Neopalatial society.