Athens allied itself with the city state of Megara which was under pressure from Corinth. This alliance leads to war between Corinth and Athens. The first battle of the war, at Haliesis in the Gulf of Argolis, resulted in a Corinthian victory, but the next battle, the battle of Cecryphalea (modern Angistrion), went Athens' way.
The Aequi occupied Tusculum. In response to the threat, the Roman Senate decided to send an army to help the allied city, under the command of consul Lucius Cornelius Maluginensis. In addition, the consul Fabius Vibulanus, who was at that point besieging Antium, moved his forces to attack Tusculum. The Tusculans were able to recapture their city. A truce was then arranged with the Aequi.
Pericles continues Ephialtes' democratising activities by making the archonship a paid office and the lower class of Athenian citizens eligible to hold the office.
The Athenians start constructing the Long Walls to protect the route from the main city to their main port (Piraeus).
Aegina joins the Peloponnesian alliance, but their combined fleet is defeated by the Athenians in the Battle of Aegina. The Athenians, under the command of Leocrates, land on the island of Aegina and besiege and defeat the city. Aegina is forced to pay tribute to Athens.
The Roman general Lucius Quinctius Cincinnatus is summoned by the Roman Senate to defend the city from attack by the approaching Aequi.[2] He is named dictator of Rome for six months. He goes on to defeat the enemy in a single day at the Battle of Mount Algidus and celebrates a triumph in Rome. Sixteen days after the battle, he resigns his dictatorship and returns to his farm.
Athenian forces block the routes back to the Peloponnese, so the Spartans decide to remain in Boeotia and await the Athenian attack. The Athenians and their allies, with 14,000 men under the command of Myronides, meet the Spartans at Battle of Tanagra. The Spartans win the battle, but they lose many men and so are unable to follow up on their victory.
The Athenians regroup after the battle and march into Boeotia. Led by Myronides, the Athenians defeat the Boeotians in the Battle of Oenophyta, and then destroy the walls of Tanagra and ravage Locris and Phocis.
Athens goes on to defeat Aegina later in the year, and to finish the construction of the Long Walls to the Athenian port of Piraeus (an action opposed by Sparta).
Boeotia, Phocis and Opuntian Locris become members of the Delian League. Athens now has enrolled in the Delian League all the Boeotian cities except Thebes. Aegina is forced to become a member of the League. It is assessed, with Thasos, for a yearly contribution to the League of 30 talents.
The first of the Athenian sculptor Phidias' monuments to Athena, the bronze Athena Promachos, is placed on the Athenian Acropolis, measuring about 9 metres high.[4]
Athens, under Athenian general Tolmides, sends 100 ships around the Peloponnesus and they set fire to the Spartan naval base at Gythion. As a result, Athens gains the agreement of the Achaean cities to join the Delian League. Athenian forces then go on to attack the Spartan allies on the Corinthian Gulf. Athens is now able to confine Sparta to the southern Peloponnesus.
The Athenians suffer a severe defeat in Egypt at the hands of the Persians. After being cut off in the Nile Delta, the Athenian fleet is defeated, and the Athenian army retreats across the Sinai Desert to Byblos before its remnants are rescued. The Egyptian rebel Inaros is crucified by the Persians. The Athenians decide against any further military activity in Egypt.
Persian rule in Egypt is finally restored by Megabyzus, satrap of Syria, after a prolonged struggle which has included dealing with a military intervention by Athens. The leader of the revolt, Inaros, is crucified by the Persians.
Pericles leads a naval expedition in the Corinthian Gulf, in which Athens defeats Achaea. He then attacks Sicyon and Acarnania, after which he unsuccessfully tries to take Oeniadea on the Corinthian Gulf, before returning to Athens.
Pericles declares that the Delian League's considerable treasury at Delos is not safe from the Persian navy and has the treasury transferred to Athens, thus strengthening Athens' power over the League.
The RomanPlebs, suffering from a number of economic and financial ills, force the city’s patricians to begin the reform and codification of the law. As a first act, a three-man commission is sent to Athens to study that city's laws.
Pericles, the ruler of Athens, bestows generous wages on all Athens' citizens who serve as jurymen on the Heliaia (the supreme court of Athens).
Achaea, on the southern shore of the Corinthian Gulf, becomes part of what is effectively now the Athenian Empire. The Delian League had changed from an alliance into an empire clearly under the control of Athens.
May 8 – The Chinese city of Jinyang is severely flooded in the Battle of Jinyang, where the elite families of Jin, Zhao, Zhi, Wei and Han fight. The Wei and the Han swap allegiances to side with Zhao and eliminate the Zhi house, ending the Spring and Autumn period of Chinese history.
The Persian fleet moves against a rebellious Cyprus to restore order. Kimon, who returns to favour, though not to power, in Athens, plans an expedition to help Cyprus. He gains Pericles' support.
An Athenian law sponsored by Pericles is passed giving citizenship only to those born of Athenian parents. This marks an end to the policy where residents who were from other cities could be given an honourable status.
Hostilities among the Greek states come to a formal end with the agreement to the Five Years' Truce. Kimon negotiates a five year truce with Sparta, in which Athens agrees to abandon its alliance with Argos, while Sparta promises to give up its alliance with Thebes. During the same year Argos signs the first "Thirty-Years Peace" with Sparta.
AtheniangeneralCimon sails to Cyprus with two hundred triremes of the Delian League. From there, he sends sixty ships to Egypt to help the Egyptians under Amyrtaeus, who are fighting the Persians in the Nile Delta. Cimon uses the remaining ships to aid an uprising of the Cypriot Greek city-states against Persian control of the island. He lays siege to the Persian stronghold of Citium on the southern west coast of Cyprus. However, the siege fails and Cyprus remains under Phoenician (and Persian) control.
During the siege Cimon dies and command of the fleet is given to Anaxicrates, who leaves Citium to engage the Phoenician fleet in the Battle of Salamis in Cyprus. The Greek fleet is victorious against the Persians and their allies and then returns to Athens.
The Athenians reduce the tribute due from their subject city-states (i.e. members of the Delian League), and each city is allowed to issue its own coinage.
5,000 talents are transferred to the treasury of the Delian League in Athens.
The success of the first Decemvirate prompts the appointment of a second Decemvirate which also includes plebeians amongst its members. This second decemviri adds two more headings to their predecessor's ten, completing the Law of the Twelve Tables (Lex Duodecim Tabularum), which will form the centrepiece of Roman law for the next several centuries. Nevertheless, this Decemvirate's rule becomes increasingly violent and tyrannical.
After minor preliminary successes (including the capture of Inessa from its Greek colonists), Ducetius, a Hellenised leader of the Siculi, an ancient people of Sicily, is decisively defeated by the combined forces of Syracuse and Acragas. Ducetius flees to exile in Corinth.
The red-figure decorations A Painter, Assistants Crowned by Athena and Victories are made on a hydria in Athens. They are now kept in a private collection (approximate date).