The collapse of the Gupta Empire can never be explained without a reference to the economic decline. The revenue income of the government was considerably reduced under the later Gupta rulers as a result of the large scale land grants made by the Gupta emperors.
The decline of the Guptas is indicated also by the supply of small quantity of coins of common use. Towards the end of the Gupta rule gold or silver coins were not in circulation. Copper coins of the period were few.
Again with the fall of the Roman Empire the commercial links with the empire also declined. Export of Indian goods stopped, consequently inflow of gold and silver was no longer there. Thus decline of trade and commerce as also insufficient revenue income were responsible for the decline of the Gupta Empire.