Even while the Olympics were occurring every four years, conflict brewed among the Greeks. The primary conflict was the Messenian wars of which there were three. It is not entirely clear when the first occurred because three historians give separate and differing accounts. They each use a different measure or calendar system. Most modern historians believe the first Messenian War likely started in 757 BC.
The precipitating events for the first Messenian War date back to approximately 400 years before. Sometime around the year 1100 BC, the Heracleidae returned to the Peloponnesus to reclaim their birth right. The Heracleidae are supposedly the direct descendants of Hercules and are, ethnically and linguistically, Dorian Greeks. These peoples conquered or supplanted the leadership of various cities and regions within the Peloponnesus. This resulted in changes to the ethnic mix of the entire Greek mainland.
Doric groups spread throughout the southern two-thirds of the Peloponnesus and the cities of Epirus; Achaeans occupied the northern portions of the Peloponnesus; Ionians occupied Attica, southern Thrace and Macedonia, various Aegean Islands, and the lands that would eventually become Ionia in Asia Minor; and Aeolians occupied Thebes and the cities of Thessaly. Conflict arose sporadically between the rulers of these cities and regions, mainly since many of the citizens were not of the same ethnic group as the rulers. These divisions. both internally and externally continued to impact Greece all the way through to the Peloponnesian War.
A distal cause of the First Messenian War involved the lineage and culture of the Kings of Messenia. The Messenians, most of whom were Achaean, were initially accepting of their new Dorian overlord, Cresphontes after he married Merope (the daughter of King Cypselus of Arcadia, who was Achaean). At some point, Cresphontes and Merope surrendered some land to a group of Dorians, forming a Dorian enclave within Messenia.
The subjects of Messenia revolted, killing Cresphontes and all but one of his children, Aepytus, who was being educated in Arcadia at the time. Once Aepytus reached adulthood, he was installed as King of Messenia by the various other Dorian monarchs in the Peloponnesus. This would later backfire on them, however, as Aepytus began a program of systematically wiping out the Dorian culture in Messenia and replacing it with his adopted Achaean culture. This enraged the Dorian subjects within Messenia and the Dorian kings who installed him to his throne.
The most proximate cause of the First Messenian War was a case of cattle rustling. Polychares of Messenia, who was an Olympic athlete, leased some grazing land from Euaiphnos of Spartan. Euaiphnos then stole the cattle and sold them, claiming raiders had ambushed the land and taken them. Polychares initially believed the explanation, but a herdsman of Polychares returned and explained what Euaiphnos had done.
Polychares was willing to let the cattle go, but Euaiphnos offered to take Polychares' son with him to pick up the money from the merchants. However, once out of Messenia, Euaiphnos killed Polychares' son. Polychares requested justice from Spartan magistrates. Justice was delayed, so Polychares decided to begin killing every Spartan he could find. After several murders, the Spartans demanded the extradition of Polychares to Sparta to stand trial. Rulers in Messenia were willing but wanted Euaiphnos in exchange.
By now, a simple case of the theft and sale of cattle had grown to involve the kings of Sparta and Messenia. Sparta dispatched a group of magistrates to Messenia to argue for the extradition of Polychares. At that time, two men ruled Messenia: Antiochus and Androcles (both were direct descendants of Aepytus). Androcles supported extraditing Polychares, while Antiochus was against it entirely.
At some point, the arguments between the rulers and the Spartan delegation boiled over, and both sides drew weapons. At the end of the fight, Androcles lay dead. Antiochus managed to calm the situation, wishing to turn the argument over to neutral arbitration (courts at Argos and Athens). None of that would happen, as Antiochus would be dead within three months, with his son Euphues succeeding him as sole King of Messenia. Shortly after his ascension, Sparta launched an invasion of Messenia.
For the first four years of the war, there was no progress by either side. In the fifth year, there was a tremendous battle near Ampheia. It was concluded indecisively, but with substantial losses on both sides. Not wanting to face such losses in the future, the Messenians fell back to a fortress at Mount Ithome. Around this time, a devastating plague struck Messenia, killing thousands of people. Distressed by mounting battlefield losses and losses at home to the plague, King Euphues sent a messenger to the Oracle at Delphi seeking advice on how to confront the Spartan threat. The Oracle instructed him to sacrifice a royal virgin, which they did. The Spartans, hearing of the Oracle's advice and the actions of the Messenians, withdrew for six years.
The war continued to wage on for years. This was a time where wars were fought in small segments between seasons and farm work. It severely restricted the time in which wars could be fought. This caused wars to last years or decades; even if the fighting could have been otherwise condensed and concluded within a few years. Though during the Messenian wars, the Greeks did advance their techniques with hoplites (career military soldiers), which made later combats more efficient.
In the 18th year of the war, several other Greek cities joined the conflict: Corinth joined with Sparta, while Arcadia and Sikyon joined with Messenia. For a short time, the tide turned in favour of the Messenians with the defeat of the Laconians, who had sided with Sparta. At some point, King Aristodemos of Messenia had a dream in which his daughter (who had been sacrificed at the suggestion of the Oracle of Delphi, appeared, and showed him her wounds). He awoke, went to her tomb, and killed himself. In the chaos that followed, the Messenians abandoned Mount Ithome, and the Spartans burned it to the ground. At this victory, the Spartans subjugated all of Messenia, reducing the remaining population to the status of helots (enslaved people), and with that, the war was over.
The Second and Third Messenian Wars each had their roots in the ashes of the first war: helot discontent. Both were widespread helot rebellions, first in 685 BC and then again in 464 BC. The first rebellion was concentrated within Messenia, where the local helots overthrew their overlords and, with the support of Argos, invaded Laconia. The initial invasion was successful, with the Messenians defeating the Spartans at the Battle of Deres. The Messenian leader of the battle, Aristomenes, was elevated by his soldiers into a king-like figure for Messenia; sharing lineage with Aepytus further cemented this.
Feeling particularly brave, or fool-hardy, Aristomenes snuck into Sparta and placed a shattered Spartan shield in the Temple of Athena to frighten the Spartans. It worked. The Spartans immediately sent for the wisdom of the Oracle at Delphi, who told them something they did not want to hear—they would need a leader from Athens to lead their armies to victory. The Spartans eventually, after suffering other battlefield losses, swallowed their collective pride to request help from Athens.
Athens sent them Tyrtaeus, who was lame (missing a leg), nearly blind, and a poet, not a military commander. Apparently, his poetry was uncommonly good, as after joining the Spartan army, the war turned in Sparta's favour, eventually trapping the Messenians in a fortress at Mount Ira. During a raid on a Spartan supply line, Aristomenes was captured.
Using the swiftness and guile that allowed him to sneak into Sparta, Aristomenes was able to slip his bonds and escape the Spartans before he could be executed, making it back to Mount Ira. The Messenians held off the Spartans for nearly a decade before surrendering. The Spartans allowed the women, children, and even Aristomenes to leave, telling those who stayed they would either die or be reduced to helot status again. Many left for Italy, settling a city at Messina. This was the end of the second war.
The Third Messenian War was a broader conflict, involving several different peoples who were subjugated as helots by Sparta. The war started in response to a devastating earthquake that struck Sparta in 464 BC. Modern analysis of the area suggests the quake had a surface wave magnitude of 7.6, which made it one of the strongest recorded earthquakes in all of antiquity. Scholars of the period put the immediate death toll between 10 and 20 thousand people. In its aftermath, the Laconians, Messenians, Thourians, and Aithaians all rebelled against Sparta. The revolt was so great the leaders of Sparta asked the other Greek city-states for assistance.
Most cities, including Athens, sent military delegations. However, Sparta concerned the Athenians had ulterior motives and would eventually turn against Sparta in support of the helots, dismissed the Athenian contingent. This infuriated the Athenians. They broke their alliance with Sparta and started building their own system of alliances. The rebellions were eventually put down, with the survivors fleeing to Athens, and then settling near Corinth. This location is important, as it is near the only land-bridge connecting Attica and the Peloponnesus. The Third Messenian War ended in 459 BC, and yet, more wars were soon to be fought. Wars that threatened the entire Greek way of life.