The various reasons that led to the fall of the Gupta empire are discussed below:
Hun Invasion
The Gupta prince Skandagupta fought bravely and successfully against the early Huns’ invasion. However, his successors proved to be weak and could not check the Huns’ invasion.
The Huns showed excellent horsemanship and were expert archers which helped them to attain success, not only in Iran but also in India. In the latter half of the 5th century, the Hun chief Toramana conquered large parts of western India, up to Eran near Bhopal in central India. By 485 CE, Huns had occupied Punjab, Rajasthan, Kashmir, eastern Malwa and a large part of central India.
Toramana (in 515 CE) was succeeded by his son Mihirkula, who was a tyrant ruler as is mentioned in the Rajatarangini by Kalhana and Hieun-Tsang refers to him as a persecutor of Buddhists. Mihirkula was defeated and the Huna power was overthrown by Yashodharman of Malwa, Narasimha Gupta Baladitya of the Gupta empire and the Maukharis. However, this win over Huns could not revive the Gupta empire.
Rise of Feudatories
The rise of feudatories was another factor that led to the fall of the Gupta empire. Yashodharman of Malwa (belonged to the Aulikara feudatory family) after defeating Mihirkula successfully challenged the authority of the Guptas and set up, in 532 CE, pillars of victory commemorating his conquest of almost the whole of northern India.
Although Yashodharman’s rule was short-lived, it certainly gave a huge blow to the Gupta empire. The other feudatories too rose in rebellion against the Guptas and ultimately became independent in Bihar, Bengal, Madhya Pradesh, Valabhi, Gujarat, Malwa and so on. It is important to mention that after the reign of Skandagupta (467 CE) hardly any coin or inscription has been found in western Malwa and Saurashtra.
Economic decline
By the end of the 5th century, the Guptas had lost western India and this must have deprived the Guptas of the rich revenues from trade and commerce and hence crippled them economically.
The economic decline of the Guptas is indicated by the gold coins of later Gupta rulers, which have less percentage of gold metal. The practice of land grants for religious and other purposes also reduced the revenues which resulted in economic instability.