Aksum minted gold when most of the world couldn't. What a coin teaches about trust

Sometime in the late third century AD, a king named Endubis did something that only a few rulers on earth could do. He had gold coins struck in his own name.

His kingdom was Aksum, in what is now northern Ethiopia and Eritrea. The coins carried his portrait, framed by ears of wheat or barley, and inscriptions in Greek, the language of Red Sea trade. They were not copies of Roman money. They were Aksum's own.

At the time, the only other powers minting gold coins were Rome and Persia, along with the Kushan empire in South Asia. An African state had put itself on that short list.

A kingdom the world counted

Aksum's wealth came from trade. Its port at Adulis on the Red Sea linked the African interior with Egypt, Arabia, India and the Mediterranean. Ivory, gold, incense and tortoiseshell moved out; cloth, glass, metalwork, wine and olive oil came in. A Greek merchants' guide from the first century AD, the Periplus of the Erythraean Sea, already describes Adulis as a trading port and names a ruler, Zoskales, whom it calls "a good man… and acquainted with Greek literature".

By the third century, Aksum was taken seriously far beyond Africa. The Persian prophet Mani, or a text attributed to his followers, named four great kingdoms of the world: Persia, Rome, Aksum and China. Aksum is the one most people today have never heard of.

Why mint your own money?

Aksum could have kept trading in barter, or in Roman coin. Instead it built its own currency in gold, silver and bronze.

Historians generally read the gold coins as money for international trade, with Greek legends aimed at foreign merchants, while the bronze and silver coins, often with inscriptions in Ge'ez, served local markets. The gold coins also seem to have been struck to a weight close to Roman standards of the time, which made them easy for traders from the Mediterranean to accept.

That is the point. A coin is a promise. It says: this piece of metal is the weight and purity we claim, and the king stakes his name on it. Merchants who had never visited Aksum could accept its coins because the promise was stamped on every one, the same way every time.

A message in metal

Aksum's coins also recorded its history. Early coins carry the disc and crescent, symbols of the old religion. Under King Ezana, in the fourth century, the disc and crescent were replaced by a cross. Aksumite coins are among the earliest anywhere to carry the cross, a record in metal of Ezana's conversion to Christianity, which is also described in inscriptions on stone at Aksum.

The coins circulated for roughly 300 years. They have turned up far from home, including in South Arabia and India. When Aksum's trade declined, from around the seventh century as Red Sea routes changed, the minting stopped too. The money lasted only as long as the trade and the trust behind it.

What a coin teaches a company

We like to think of trust as a feeling. Aksum shows it is also infrastructure. Its merchants did not ask strangers to trust them personally. They built something standard, measurable and verifiable, stamped it with a name, and put it into circulation.

Every business runs on promises like that. An invoice says these goods were delivered. A label says this pack weighs 500 grams. A certificate says this batch passed its tests. A balance sheet says this is what we own. Each of them is a coin of sorts: a claim that strangers will accept only if it is consistent, checkable and backed by someone willing to put their name on it.

African businesses are often told to "build trust" with buyers, investors and partners abroad. Aksum's answer, 1,700 years ago, was not to ask for trust but to issue it: to make your promises so standard and so verifiable that the other side does not need to know you personally.

So here is the question Endubis leaves us: what promises does your business make every day, and could a stranger check them?