Kausambi in the context of "Alchon Huns"

Hunas or Huna (Middle Brahmi script: Hūṇā) was the name given by the ancient Indians to a group of Central Asian tribes who, via the Khyber Pass, entered the Indian subcontinent at the end of the 5th or early 6th century. The Hunas occupied areas as far south as Eran and Kausambi, greatly weakening the Gupta Empire. The Hunas were ultimately defeated by a coalition of Indian princes that included an Indian king Yasodharman and the Gupta emperor, Narasimhagupta. They defeated a Huna army and their ruler Mihirakula in 528 CE and drove them out of India. The Guptas are thought to have played only a minor role in this campaign.

The Hunas are thought to have included the Xionite and/or Hephthalite, the Kidarites, the Alchon Huns (also known as the Alxon, Alakhana, Walxon etc.) and the Nezak Huns. Such names, along with that of the Harahunas (also known as the Halahunas or Harahuras) mentioned in Hindu texts, have sometimes been used for the Hunas in general; while these groups (and the Iranian Huns) appear to have been a component of the Hunas, such names were not necessarily synonymous. Some authors suggest that the Hunas were Hephthalite Huns from Central Asia. The relationship, of the Hunas to the Huns, a Central Asian people who invaded Europe during the same period, is under research.

The Alchon Huns, (Bactrian: αλχον(ν)ο Alkhon(n)o or αλχαν(ν)ο Alkhan(n)o) also known as the Alkhan, Alchono, Alxon, Alkhon, Alakhana, and Walxon, were a nomadic people who established states in Central Asia and the Indian subcontinent during the 4th and 6th centuries CE. They were first mentioned as being located in Paropamisus, and later expanded south-east, into the Punjab and Central India, going as far as Eran and Kausambi. The Alchon invasion of the Indian subcontinent eradicated the Kidarite Huns who had preceded them by about a century, and contributed to the fall of the Gupta Empire, in a sense bringing an end to Classical India.

The invasion of India by the Huna peoples follows invasions of the subcontinent in the preceding centuries by the Yavana (Indo-Greeks), the Saka (Indo-Scythians), the Pahlava (Indo-Parthians), and the Kushana (Yuezhi). The Alchon Empire was the second of four major Huna states established in Central Asia and the Indian subcontinent. The Alchon were preceded by the Kidarites and succeeded by the Hephthalites and Nezak Huns in Bactria and the Hindu Kush respectively. The names of the Alchon kings are known from their extensive coinage, Buddhist accounts, and a number of commemorative inscriptions throughout the Indian subcontinent.