Hellenization was the spread of Greek culture and the assimilation into Greek culture of non-Greek peoples. It was a notable trait of ancient Greek civilization, an approach to other cultures that was not merely invasive or dominant but transformative.

This set an example later followed by the Roman Empire, Christianity, and the British Empire, essentially establishing a framework within which much of Western history can be discussed.

The products of culture spread by Hellenization included the Greek language and writing system, its myths and religion, and its technology and art—not mere ideas but practical and exploitable benefits.

The Hellenes, or Greeks, were so-called by classical writers because they were the descendants of Hellen, the son of Deucalion (son of Prometheus) and Pyrrha (daughter of Epimetheus and Pandora). They were assimilators from the start.

When they came to inhabit the isles and mainland of what is now Greece, they displaced the indigenous Pelasgians, bringing with them some form of their writing, language, religion, and art. The Pelasgians were unrelated to the Hellenes in any significant sense: Some modern scholars even believe their language was pre-Indo-European, unintelligible to the Greeks on first contact.

The native culture was soon absorbed into that of the new arrival. Though Herodotus attests to some Pelasgian groups surviving with mutually intelligible language, most intermarried and became fully Greek, invisible, and largely forgotten.

The most important period of Hellenization by far was that which transpired under the reign of Alexander the Great. Extending the reach of his rule to staggering extents after his father’s unification of the Greek city-states—to Egypt, India, Persia, and across the eastern Mediterranean—Alexander did not limit this rule to simple military conquest and tribute collection.

He integrated his army, allowing non-Greek, non-Macedonian troops in the same units as natives and strongly encouraging intermarriage with foreign women to blur the barriers between the conquering and conquered peoples.

He set up schools to teach children Greek language and culture and built gymnasiums, cultural centers associated with exercise (especially gymnastics and wrestling), medicine, and communal bathing, in the cities he conquered. The gymnasium was at the center of social culture in ancient Greece, much like the public houses of medieval Europe.

Upon Alexander’s death, though, the widespread nature of Greek civilization gave way to the so-called Hellenistic Period. Under Alexander, Greek cities had diminished in importance to Greek culture, sharing their influence over the social, economic, and intellectual world with new additions such as Alexandria and Rhodes.

The world became more Greek, but Greece in turn became worldlier, and especially more Persian. It would not be so centralized again until the fall of the Roman Empire in the West left Constantinople as the capital of the Byzantine Empire.

In the meantime even Roman-controlled areas became more and more Hellenized. Greek was the language of trade and culture, the common tongue necesary for travelers. Palestine became strongly Hellenized, to the extent that Greek forms of names displaced the Semitic originals—with Yeshua becoming Jesus, for instance. More and more Jewish leaders feared that their people would lose their identity.

Many Jewish practices and movements in antiquity were thus responses to Hellenization, whether they were revolutionary movements that sought to restore Jewish self-governance and an exclusivity of culture or syncretic sects that blended traditional Jewish religion with pagan elements.

Whatever Jesus (Christ) of Nazareth’s contact with Greek culture, Christianity became extremely Hellenized in the wake of his death. The New Testament was written in Greek, and many early Christians were proselytes, Greek-speaking Gentiles who followed Jewish cultic practices without converting.

The sophistication of Pauline theology, the Johannine books (the Gospel and Revelation of John), and the writings of the early apostolic fathers up to and including Augustine of Hippo were deeply influenced by Greek philosophy and the Hellenized intellectual climate of the Roman Empire.

The concept of Logos so central to Johannine Christology—the Gospel of John states in its first verse, "in the beginning was the logos, and the logos was with God, and the logos was God"—was not simply a Greek word which loses significance in translation (commonly translated as "word", it also means logic, reason, principle, and thought), but a well-explored concept in Greek philosophy.

Heraclitus had used it in reference to the order and rationality of the universe, and Aristotle, in developing his system of logic. The Stoics, who may have influenced Jesus or his followers and certainly had much in common with them, formulated logos as the engine of creation, the underlying force that gave life to existence.

After the fall of Rome the Byzantine Empire identified itself strongly as a Hellenic Christian empire: ethnically Greek, religiously Christian, and the inheritors of both classical Greek culture and the Roman right of rule.

Surrounded by Persian and, later, Muslim enemies, it underwent several periods of Hellenic revival, with "Greek" and "Christian" increasingly associated together—the final step in the long history of Hellenization.