Predynastic Egyptian archaeological sites prove that even before Egypt was a unified empire, human settlements along the Nile traded for copper, timber, wine, and oils with Mesopotamia and the surrounding area.

The Sahara was a major impediment to trade with the interior of the African continent, and the Songhai empire existed in the late Middle Ages.

The Roman empire was ancient, but still thousands of years after predynastic Egypt.

Likewise, the Athenian empire was ancient but thousands of years after predynastic Egypt.

The Shang kingdom of China was thousands of years after Predynastic Egypt, and too far away to have any sustained trade with north Africa.

Throughout much of the ancient period, before the rise of Greece, Persia, and Rome, the ancient Phoenicians created an extensive commercial empire in the Mediterranean. They were able to dominate trade due to their sophisticated alphabet and their establishment of settlements throughout the Mediterranean.

The city-states of Tyre, Sidon, and Byblos were once all part of the Phoenician empire. The Phoenician empire was a wide-ranging commercial empire that controlled trade in the Mediterranean from about 1,300 BCE until 500 BCE.

Silk was first produced in China during the Shang Dynasty. For the next thousand years, China enjoyed an effective monopoly on silk production (as they were the only people who knew how to do it). This contributed to the growing wealth of the Chinese emperors as silk was traded extensively with empires in Europe (such as the Romans) and the Middle East (such as the Persians).

The ancient commercial empire of Phoenicia was established in modern-day Lebanon approximately 1,500 BCE.

An imperial supply chain facilitated a sophisticated and diverse Roman economy, especially luxuries for the Roman elite like a thriving silver sector based on raw materials sourced from Britannia and Hispania but worked into ornaments and jewelry in Rome, as well as nearby cities on the Italian Peninsula, and certain special cities like Trier, which were nominally equidistant between Britannia, Hispania, and Rome.

Rome's supply chain was a classic colonial enterprise, based on raw materials sourced from the periphery, and luxury goods crafted by artisans in sophisticated workshops in the center of power; raw materials were most often not constructed into ornaments or jewelry in far flung provinces.

Although a minority of silver may have been given to Egyptian officials in exchange for grain, silver retains value whereas grain is consumed; empires are constructed in the process of expanding control by a center of power, and dumping huge amounts of precious substance like silver into Egypt would increase the power of Egypt instead of Rome itself. The Roman elite would have been careful to keep the majority of silver in their own hands.

Although certain members of the Roman elite may have cared for the orphans of war, Roman authorities wanted silver for luxury goods.

Damascus Steel was a type of metal forged in the Middle Ages, not during the time of Ancient Rome.

Alexandria was the political capital of Egypt at the time, and Egyptian grain, as well as Egypt's navy, were vital to Caesar's attempts at dictatorship.

Sparta was a military power during the Greek Golden Age, a period of well-documented philosophical, architectural, and artistic output.

Athens was a cultural and naval power during the Greek Golden Age, never a major producer of grain.

Carthage was a major antagonist in multiple wars against the Roman Empire.

Troy was a major proponent in the semi-historical Trojan War between the cities of Troy and a league of Hellenes led by Agammemnon.

At the height of its power the Roman Empire effectively controlled the entirety of the Mediterranean. This made trading and sailing relatively efficient and safe (so long as one was a member of the Roman Empire). The Roman navy patrolled the seas and protected traders from the plundering efforts of pirates and rival civilizations.

Silk production had long been a Chinese state secret when a small group of Byzantine monks smuggled silkworms back from China in the sixth century. This led to the breakdown of the Chinese monopoly and the further growth of the Byzantine Empire as the wealthiest in Europe.

The Grand Canal is the longest canal or artificial river in the world. It starts in Beijing and links the Yangze and the Huang He rivers. It was completed during the Sui dynasty (581-618 CE).