When the grape harvest determined alliances in the Peloponnesian War
We will leave aside Greek mythology, which attributes the creation of wine to the god Dionysus, the Roman Bacchus, and place the island of Crete as the gateway of wine to the Greek polis. Crete thus served as a bridge between Pharaonic Egypt and Greece.
Unlike in Mesopotamia or Egypt, where wine was a luxury item only available to the wealthier classes or for special celebrations, in ancient Greece, given the climatic and soil conditions, wine became an affordable product that all social classes could afford.
The words of Thucydides, a Greek historian of the 5th century BC, are revealing of the importance that wine acquired...
"The peoples of the Mediterranean began to emerge from barbarism when they learned to cultivate the olive tree and the vine".
In addition to improving viticultural techniques and winemaking processes that increased vine yields, the Greeks were the first to produce wine on a commercial scale, making it one of the main export products. They took the culture of wine to all their Mediterranean colonies and even among the Greek polis themselves, the cultivation of cereals was gradually replaced by that of vines, to the point that many city-states had to import the once surplus grain. Such was the importance of wine for Greece that it even determined the alliances in the Peloponnesian War.
The Peloponnesian War (431-404 BC) was a military conflict that pitted the League of Delos (an association of several city-states in Attica and the Aegean islands led by Athens) against the Peloponnesian League (an alliance of Peloponnesian states led by Sparta). One of the cities that had been part of the League of Delos since its foundation was Acanthus on the peninsula of Chalkidiki. But all that was to change in 424 BC ....
In 424 BC General Brasidas took command of the army of Sparta and marched over the Isthmus of Corinth, foiled an Athenian attack on Megara and halted the advance of the Delian League. From there he marched north through Thessaly to the Chalcidic peninsula, arriving at the gates of Acanthus just before the grape harvest. Fearing for their grapes, since it was logical to think that if the Spartans took the city they would not respect their crops, like good Greeks they voted on what to do... they changed their alliance and decided to associate with Sparta. That way, they were able to harvest the grapes without any problems and make their wine.