Ephthalites was the name given by Byzantine historians and Hayathelaites by the Persian historian Mirkhond, and sometimes Ye-tai or Hua by Chinese historians. They are also known as the White Huns, different from the Hun who led by Attila invading the Roman Empire. They are described as a kindred steppe people originally occupied the pasture-lands in the Altai mountain of southwestern Mongolia.

Toward the middle of the 5th century, they expanded westward probably because of the pressure from the Juan-juan, a powerful nomadic tribe in Mongolia. Within decades, they became a great power in the Oxus basin and the most serious enemy of the Persian empire.

The Westward Expansion and War with Sassanian Empire
At the time when the Hephthalites gained power, Kushan and Gandhara were ruled by the Kidarites, a local dynisty of Hun or Chionites tribe. The Hephthalites entered Kabul and overthrew Kushan. The last Kidarites fled to Gandhara and settled at Peshawar. Around 440 the Hephthalites further took Sogdian (Samarkand) and then Balkh and Bactria.

The Hephthalites moved closer and closer toward Persian territory. In 484 the Hephthalite chief Akhshunwar led his army attacked the Sassanian King Peroz (459-484) and the king was defeated and killed in Khurasan. After the victory, the Hephthalite empire extended to Merv and Herat, which had been the regions of the Sassanid Empire. The Hephthalites, at the time, became the superpower of the Middle Asia. They not only destroyed part of Sassanian Empire in Iran but also intervened in their dynastic struggles when the Sassanid royal, Kavad (488-496), was fighting for the throne with Balash, brother of Peroz. Kavad married the niece of the Hephthalites chief and the Hephthalites aided him to regain his crown in 498.

After conquest of Sogdia and Kushan, the Hephthalites founded the capital, Piandjikent, 65 kilometers south-west of Samarkand in the Zaravshan valley. This city later reached its prosperity, produced one of the best mural paintings in the seventh century and later was destroyed by the Arabs. The Hephthalites chose Badakshan as their summer residence. Their chiefs lived north of the Hindu Kush, migrating seasonlly from Bactria where they spent the winter, to Badakshan, their summer residence. Under the Hephthalite control, the Bactrian script and language continued to be used and trade and commerce flourished as previously.

The Eastward Expansion to the Tarim Basin
With the stabilization at the western border, the Hephthalites extended their influence to the northwest into the Tarim Basin. From 493 to 556 A.D., they invaded Khotan, Kashgar, Kocho, and Karashahr. The relationship with Juan-juan and China were tightened. The Chinese record indicated that between 507 and 531, the Hephthalites sent thirteen embassies to Northern Wei (439-534) by the king named Ye-dai-yi-li-tuo.

Invasion to India
During the 5th century, the Gupta dynasty in India reigned in the Ganges basin with the Kushan empire occupied the area along the Indus. India knew the Hephthalite as Huna by the Sanskrit name. The Hephthaltes or Hunas waited till 470 rigth after the death of Gupta ruler, Skandagupta (455-470), and entered the Inda from the Kabul valley after the conquest of Kushan. They mopped on along the Ganges and ruined every city and town. The noble capital, Pataliputra, was reduced in population to a village. They persecuted Buddhists and burned all the monasteries. Their conquest was accomplished with extreme ferocity and the Gupta regime (414-470) was completely extinguished.

For thirty years the northwestern India was ruled by Hephthalite kings. We learned some of the Hephthalite kings ruling India from coins. The most famous ones were Toramana and Mihrakula ruling India in the first half of the 6th century.

The Language
There are numerous debates about Hephthalite language. Most scholars believe it is Iranian for the Pei Shih states that the language of the Hephthalites differs from those of the Juan-juan (Mongoloid) and of the "various Hu" (Turkic); however there are some think the Hephthalites spoke Mongol tongues like the Hsien-pi (3rd century) and the Juan-juan (5th century) and the Avars (6th-9th century). According to the Buddhist pilgrims Sung Yun and Hui Sheng, who visited them in 520, they had no script, and the Liang shu specifically states that they have no letters but use tally sticks. At the same time there is numismatic and epigraphic evidence to show that a debased form of the Greek alphabet was used by the Hephthalites. Since the Kushan was conquested by Hephthalites, it is possible they retained many aspects of Kushan culture, including the adoption of the Greek alphabet.

The Religion
It is equally inconsistent while comparing the references to the Hephthalites' religion. Although Sung Yun and Hui Sheng reported that the Hephthalites did not believe in Buddhism, though there is ample archaeological evidence that this religion was practiced in territories under Hephthalite control. According to Liang shu the Hephthalites worshiped Heaven and also fire - a clear reference to Zoroastrianism. However the burials found seem to indicate the normal practice in disposing of the dead, which is against Zoroastrian belief.

The Customs
Very little was known about these Hephthalite nomads. Little art has left from them. According to Sung Yun and Hui Sheng who visited their Hephthalite chief at his summer residence in Badakshan and later in Gandhara,

Other than the deformation of skulls, the other interesting feature of the Hephthalites is their polyandrous society. The records of brothers marrying to one wife had been reported from Chinese source.

The Extermination
Between 557 to 561 Persian King Chosroes allied with another steppe people who had appeared from inner Asia. Chorsoes wanted to profit from the situation to take revenge over the defeat of his grandfather Peroz; he married a daughter of the nomadic chief and allied himself with them against the Hephthalites. The chief Sinjibu was the boldest and strongest of all the tribes and he had the largest number of troops. It was he who conquered the Hephthalites and killed their king.

Mercileessly attacked on two sides, the Hephthalites were completely broken and disappeared by 565 that only small number of them survived. Some surviving groups living south of Oxus escaped Chosroes' grasp later fell to Arab invaders in the 7th century. One of the surviving groups fled to the west and may have been the ancestors of the later Avars in the Danube region. The decline of the Hephthalites marked a turning point in the story of the steppes. Another era was opening in Central Asia. For the allies of Chosroes were Western Turks, a new power was to dominate the steppe for next few centuries.