In 332 BC, the Persian satrap of Egypt surrendered to Alexander the Great without a struggle. Alexander was accepted as pharaoh and, on visiting the oracle of Amun at Siwa, was acclaimed as a god. The young Macedonian conqueror laid the foundations of Alexandria in the western delta and made plans for Egypt's administration. Native governors were appointed and arragements made for a tax collection.

After Alexander's death in 323 BC, his general Ptolemy, son of Lagus, took the young king's body for burial to Alexandria, where a great tomb was built. In doing this, Ptolemy symbolically linked himself and his successors to the divine pharaoh and founder of the city. In 305 BC, Ptolemy declared himself king of Egypt and became the first of a line that ruled Egypt until the end of the reign of Cleopatra VII when, in 30 BC, the country was taken over by Rome. The Ptolemies took pharaonic titles and paid honor to the Egyptian gods, which gave them the support of the preists. Outwardly, Egyptian life was much as it had been in the pharaonic times but, in fact, the interests of the local inhabitants were subordinated to those of their new masters.

The Ptolemaic period was a time of great contrasts. Alexandria was a great center of Hellenistic culture, having the world's first museum and the largest library of its time. Medicine, mathematics and geography flourished. The Egyptians, however, were subjected to heavy taxes and other conditions that resulted in increasing poverty. Farmers had to lease their land from the state, which regulated the type and quantity of crops that they might grow each year. They had to maintain the canals, pay a tax in grain and allow the state to buy part of their crop at a fixed price. Industries also had to pay heavy taxes, and certain commodities were state monopolies. As time went by, strikes and flight from the land became quite common, and toward the end of the period, there was unrest and rural depopulation.

Under Roman rule, the country's administration was reorganized, and steps were rapidly taken to halt the agricultural decline. Egypt became the granary of Rome, and its importance is underlined by the fact that, unlike other Roman provinces, it was under the direct control of the emperor. Peace, security, and efficient government brought a remarkable economic recovery, and agricultural production increased and commerce flourished. Nevertheless, this propserity benefitted Rome, not Egypt.

Little is known of the Egyptians themselves during the first two centuries of Roman rule. The ancient cults were maintained and temple building continued, but the temple lands were now owned by the state, and the preisthood was controlled by a Roman civil official. The hieroglyphic script, except for texts carved on the walls of the temples in Upper Egypt, was abandoned. By the end of the second century AD, there were revolts and increasing lawlessness. The political, social, and cultural decline of the Egyptians made them ready converts to Christianity. First brought to Alexandria, this new, universal religion spread rapidly. Several of the early church fathers were Egyptian, and it was here that monasticism first developed.