The Egyptian-Athenian victory is short-lived: the Persians, led by Megabyzus, the new satrap of Syria, together with Artabazus, satrap of Phrygia, who arrive in 456 BCE, now counterattack, confronting the Athenian fleet blockading Memphis, destroying two squadrons and confining the remainder of the Greek fleet, along with the Egyptian rebels, to an island in the Nile, where the Persians besiege them.

Charitimides is killed and Inarus is wounded in the thigh by the Persian force; he retreats to Byblus, his stronghold and the only Egyptian city that does not submit to Megabyzus.

The Athenians in 456 BCE defeat the Thebans at Oenophyta, which will give them control of Boeotia for a decade, an extremely important development.

The helots' revolt, suppressed by Sparta with difficulty, lasts for ten (or possibly only four) years.

Messenian resistance, which had begun to flag in 457, ends in 455 with the fall of Mount Ithome.

The surviving Messenians, freed by the Spartans but exiled from the Peloponnesus, join Athens in their ongoing larger conflict with Sparta.

The Athenians take further aggressive Athenian action under the general Tolmides, who in 456 had circumnavigated the Peloponnese and perhaps settled the large number of Messenians at Naupactus alongside the original Naupactans.

Persian military engineers change the course of the Nile in 454 BCE to finally crush the defending Egyptian rebels and their Greek allies.

Inaros, after fighting for a year and a half in the marshes, is defeated by Megabyzus and taken captive, together with the Greeks, away to Susa.

Pericles launches a naval expedition in the Corinthian Gulf in 454 BCE, in which Athens defeats Achaea, seizing a long coastal strip, but fails to win more important objectives.

The Athenians, having received the vassalage of Sparta's restive helots, order them to colonize the Gulf region.

Pitsunda, today a resort town in the Gagra district of modern Abkhazia, the breakaway republic of Georgia, situated on the shore of the Black Sea twenty-five kilometers south from Gagra, is founded by the Greeks in the fifth century BCE as a trade colony called Pityus or Pitiunt.

The Celtic migration of the mid-fifth century (commonly known as the La Tene phase of Celtic culture) marks the transition from the Early to the Late Iron Age in Europe.

Etruscans had begun widely exporting to the north a type of bronze pitcher, the so-called “Schnabelkanne," or beaked pitcher, around the beginning of the fifth century.

The Celts of the La Tene culture have begun to copy these and develop their own sense of style, usually making them in bronze or clay.

The most famous Celtic beaked pitchers come from the Hessian Glauberg and the Dürrnberg in Hallein in Austria, which are considered Celtic developments.

The Middle East: 453–442 BCE

The Peace of Callias and Persian Consolidation

In 449 BCE, Artaxerxes I concludes an agreement known as the Peace of Callias, named after the Athenian ambassador and Marathon veteran, Callias, who purportedly negotiates this accord. Although the historicity of a formal treaty remains debated, the arrangement effectively recognizes Athenian control and influence over the city-states of the Greek mainland and the islands of the Aegean Sea.

This peace marks a significant diplomatic moment, indicating Persian willingness to acknowledge, at least implicitly, a limit to its westward expansion. Artaxerxes's focus shifts inward, consolidating authority within existing imperial boundaries and continuing to address regional stability. The Persian Empire, though politically intact and still extensive, must manage ongoing tensions and administrative challenges in its far-flung satrapies, while recognizing practical limits to its imperial ambitions.

Mediterranean naval architects in the mid fifth century BCE, increase a ship's carrying capacity by building up its bulwarks.

Some ships by this time step two masts, with a sail hoisted on each.

These broad-beamed trading vessels are known as "round ships."

The Greeks increase their size.