Who the Kushans were, and who they were not
The Kushan Empire was a state that held Bactria (roughly northern Afghanistan and neighbouring Central Asia) and a large part of northern India for about two centuries, broadly from the 1st to the 3rd century CE. It was founded by a people that Chinese sources call the Yuezhi. Despite the similar name, it has no connection with the Kingdom of Kush in Africa, which belongs to the history of the Nile and the Nubian civilization. The resemblance is an accident of spelling in modern languages.
The word “forgotten” in the title needs a caveat. Specialists have studied the Kushans for generations, and their coins, inscriptions and Buddhist monuments are well known in museums. What is true is that the empire left few long narrative texts of its own, so its history has to be pieced together from coins, inscriptions and the accounts of its neighbours. Many details, including exact dates, remain debated.
From the Yuezhi to a kingdom in Bactria
Chinese histories describe the Yuezhi as a people living in the north-west of China in the 2nd century BCE. Pushed westward by the Xiongnu confederation, they moved through Central Asia and eventually settled in Bactria, where earlier Greek rulers had left cities, coinage and a Greek-influenced culture. Alexander’s campaigns, including the clash remembered as Alexander versus Darius, had brought Greek settlers to this region two centuries earlier, and their legacy shaped what the newcomers inherited.
Chinese accounts say the Yuezhi were first divided among five chiefs. One of them, usually identified as Kujula Kadphises, is credited with uniting them around the 1st century CE and expanding south over the Hindu Kush into Gandhara. His successor, Vima Kadphises, is associated with a large issue of gold coins, which suggests a wealthy state with access to bullion and trade.
Kanishka and the height of the empire
The best-known Kushan ruler is Kanishka. The date of his accession was argued for decades; many specialists now favour a date around 127 CE, though earlier proposals once had wide support. His reign is usually placed in the second quarter of the 2nd century CE.
Inscriptions and finds suggest that under Kanishka and his immediate successors the empire reached from Bactria across Gandhara and the Indus region into the Ganges plain, with major centres at Peshawar (then called Purushapura) and Mathura. The extent of the eastern and northern borders is less certain. Some claims about Kushan control over oases on the edge of the Tarim Basin rest on limited evidence and are still discussed.
An important inscription found at Rabatak in Afghanistan is written in Bactrian, an Iranian language, using an adapted form of the Greek alphabet. It shows that Kanishka made this language official, a striking sign of how much Greek influence had lasted. The empire was truly multicultural: Greek, Iranian and Indian traditions coexisted in its administration, coinage and religion.
Coins, religion and Buddhist art
Kushan coins are among the best evidence for the empire. Gold issues carry portraits of the rulers and images of deities drawn from Greek, Iranian and Indian traditions, often with Greek-script legends. The range of gods suggests a ruling class that did not insist on a single religion. Details of coin minting, including how gold was standardised against nearby currencies, are still studied by numismatists.
Kanishka is remembered in Buddhist tradition as a patron. Later texts describe him sponsoring a council and building a large stupa near Peshawar, though how much of this is historical is debated. What is clearer is that the Gandhara region produced a distinctive Buddhist art in this period, with stone and stucco figures that show Greek and Roman influence in drapery and form. Mathura developed its own Indian sculptural tradition at the same time. Kushan patronage helped carry Buddhism along trade routes into Central Asia and, later, China.
Trade across Eurasia
The empire sat between four large worlds: Rome, Parthia and later Persia, India and Han China. Merchants moved silk, spices, glass, metalwork and other goods across Kushan territory, a major piece of the wider Silk Road trade routes. Sogdian merchants and others from Central Asia took part in the commerce that followed.
The clearest picture of this exchange comes from the site of Begram in Afghanistan, where two sealed rooms held a mixed collection of objects. They included Roman-style glassware and bronzes, Indian ivory carvings and Chinese lacquer, all in one place. Archaeologists debate whether Begram was a royal treasury or a merchant store, but it shows how many cultures met in Kushan cities. Maritime links also mattered; the monsoon trade winds carried goods between India and the Roman world, and Kushan ports and markets were well placed to benefit.
Han China and the Kushans were also in contact. A Chinese source describes a clash around 90 CE with the general Ban Chao, after the Kushans asked for a marriage alliance, though the account comes from Chinese sources and its details are hard to check independently.
Decline and defeat
The Kushan state weakened in the 3rd century CE. In Iran the Sasanian dynasty overthrew the Parthians in the 220s and soon turned east. Over the following decades the Sasanians took control of Bactria and the western Kushan lands, and a line of governors sometimes called Kushano-Sasanians ruled there under Sasanian authority. The exact chronology of this conquest is not fully settled.
In India, Kushan rule fractured into smaller kingdoms and Kushan princes continued in parts of the north-west for a time, until other powers such as the Gupta rulers gained the upper hand in the 4th century. Further waves of steppe peoples then moved into the region, including the Kidarites and later the Hephthalites. Some of these groups echo the earlier Hunnic migrations, although their precise relationship to the Huns of Europe is disputed.
Why the Kushans matter
The Kushan Empire helps explain how religions, artistic styles and goods moved across Eurasia in the early centuries CE. Its rulers governed a mixed population, used an adapted Greek script for an Iranian language, issued coins that honoured gods from several traditions, and supported a Buddhist art that influenced later Asian styles. The empire left no single great capital that survives as a famous ruin, and that is a large part of why it is less familiar than Rome or Han China, even though it was a contemporary of both.