http://www.wsu.edu/~dee/ANCINDIA/GUPTA.HTM The Guptas tended to allow kings to remain as vassal kings; unlike the Mauryas, they did not consolidate every kingdom into a single administrative unit. This would be the model for later Mughal rule and British rule built off of the Mughal paradigm.
The Guptas fell prey, however, to a wave of migrations by the Huns, a people who originally lived north of China. The Hun migrations would push all the way to the doors of Rome. Beginning in the 400's, the Huns began to put pressure on the Guptas. In 480 they conquered the Guptas and took over northern India. Western India was overrun by 500, and the last of the Gupta kings, presiding over a vastly dimished kingdom, perished in 550. A strange thing happened to the Huns in India as well as in Europe. Over the decades they gradually assimilated into the indigenous population and their state weakened.
The Huns certainly reached India. Ever heard of Mrihakula, the Hun emperor who invaded India incl. present-day Afghanistan and Pakistan? He subsequently converted to Shaivaism and settled deown in present-day Jammu and Kashmir.
Indian history is replete with references to the Hunas, the Sanskrit word for Huns.