So there is some debate about the origins of the Hepthaltites still, because the primary source information about them is rather contradictory. Chinese sources attribute their origins to either the Jushi (an ancient tribe north of the Tupan depression), Kang'ju (An Indo-Iranian kingdom between the Syr and Amu Darya rivers and around the Aral sea), or the Da Yueh'zhi (A Tocharian people the Xiongnu had driven out of the Hexi Gansu in the 2nd Century BC, widely believed to be related to the Kushans). Literature from the region of their brief empire dating to the 5th-6th centuries in Bactria, Sogdia, and parts of India identifies them largely as Bactrian, or at least calls them by Bactrian names and titles. The problem with Chinese attempts to connect them to ancient peoples is that Chinese sources like the Weishu are typically copying earlier works (much like Roman authors liked to copy Herodotus). The text of the Weishu and Beishi on these peoples is copied from the earlier Zhoushu and Suishu, and really all it does is identify the region the Hepthaltites were in during the 5th/6th centuries to their Chinese audiences who would have understood it via identifying them with the Yuezhi. But it's not as clear cut as that either, since the local remnants of the former Kushan empire did make up a part of the Hepthaltites.

The best reconstruction modern Historians currently offer is that the Hepthaltites were a people known to the Chinese as the Hua, a vassal group of the Rouran (a steppe people often idenfitied with the later Avars but who actually have no relation, that spoke an as-yet unknown language which formed the basis for many words in Old Turkic. I wouldn't put it past them speaking a branch of Yeniseian like the Xiongnu/Huns.) who lived just beyond the western parts of the Great Wall, north of the Turfan Depression and Hexi Gansu regions. During the 5th century, the Hua were attacked by their Rouran overlords and broke up, some of whom migrated into the state of Northern Wei (who would then appear in the fictional tale of Hua Mulan, a steppe nomad girl settled by the Northern Wei in one of the Great Wall militia villages who would go and fight for the Rouran Qagan). Another group emigrated North of Xingjiang (the Tarim Basin) through the territories of the Yueban (the "weak Huns") and Wusun (an Alan people) and into Bactria, some time in the mid-5th century AD.

At that time Bactria was under the rule of a people known as the Kidarites or Khionites, who were proper Huns (and are sometimes called the "Red Huns"). They were descended from the Xiongnu who had migrated into Central Asia in the mid-4th century and then broke up when a mega-drought hit in about 360, driving them into Afghanistan and Europe. Likewise, megadrought was probably the cause of the Hepthaltite migration considering the next in the cycle occurred about 430 AD, about the same time the Rouran attacked the Hua and then the Hua migrated into Bactria. The Khionites can be identified by the use of votive figures of feasting companions found in their burials, a practice actually mentioned by Roman authors including Ammianus and Procopius, which descended from the custom of burying slaves and other companions with their owners/patrons in the pre-Scythian and Scythian periods. I will note that I am not aware of any evidence the European Huns performed this practice, although we know the Kidarites were directly related to them. The Hepthaltites also performed this practice, and so did other peoples in South Siberia and the Altai range, and it appears to have been common among many of the Old Turkic (Oghur) speaking peoples. However, it should be remembered that the majority of these groups were actually local Bactrians and Sogdians, and the only elements of them that came from Steppe nomads were typically the aristocracy. This is why we often refer to them as the Kidarite or Hepthaltite dynasties rather than as peoples, since they were named after their ruling class.

The decline of the Kidarites and the successful wars of Bahram V and Yazdegerd II against them during the 430's and 440's coincides with the coming and establishment of the Hepthaltites as a power in Sogdia and Bactria, who forced the Kidarites west to the region north of the Great Wall of Gurgan (the world's second largest great wall, also built to keep out the Huns like the first great wall) between the Aral sea and the Caspian sea. However, the Hepthaltites by and large do not come into the greater picture until about 450-451, when Armenian sources record that the Sassanids undertook a great campaign into Eptagan and were victorious. In 453-4, the Sassanids undertook a second campaign but were badly defeated, although this may have been by the Kidarites, not the Hepthaltites.

The Hepthaltites come to power under the reign of Perozh, through a brief Sassanid civil war. This resulted in the vassalization of the Sassanids, where Perozh agreed to hand over lands in northern Pakistan and northeast Iran and tribute in exchange for an army of about 30,000 men, to put him in power in place of his older brother. After years of famine around 460, which also impacted the Hepthaltites and drove the Tieh'le, Xianbei, and other peoples into the west (known to the Romans as the various Oghurs and the Sabirs), Perozh campaigned against the Kidarites around 464, and took their capital Balaam (east of the Turkmenbashi Bay in Turkmenistan) in 468. The Hepthaltites, still the overlords of the Persians, assisted them in this campaign when they had attacked the Kidarites in Transoxiania in 466. The last of the Kidarites would remain in Gandhara until they were overrun by a new wave of invaders, the "Alkhon Huns", sometime after 477.

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