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 ones to have invaded Northern India were called "Hunas" in Sanskrit, not entirely clear if they were the same as the Central Asian Huns. BTW PTI is a very reliable source.
BTW this is a very interesting article from Mosnews.com:
Ancient Vishnu Idol Can Change View on Russian History
Created: 04.01.2007 14:18 MSK (GMT +3), Updated: 14:18 MSK, 3 hours 26 minutes ago
MosNews
An ancient Vishnu idol has been found during excavation in an old village in Russia’s Volga region, raising questions about the prevalent view on the origin of ancient Russia, the Reuters news agency reports.
The idol found in Staraya (old) Maina village dates back to VII-X century AD. Staraya Maina village in Ulyanovsk region was a highly populated city 1700 years ago, much older than Kiev, so far believed to be the mother of all Russian cities.
“We may consider it incredible, but we have ground to assert that Middle-Volga region was the original land of Ancient Rus. This is a hypothesis, but a hypothesis, which requires thorough research,” Reader of Ulyanovsk State University’s archaeology department Dr Alexander Kozhevin told state-run television Vesti .
Dr Kozhevin, who has been conducting excavation in Staraya Maina for last seven years, said that every single square metre of the surroundings of the ancient town situated on the banks of Samara, a tributary of Volga, is studded with antiques.
Prior to unearthing of the Vishnu idol, Dr Kozhevin has already found ancient coins, pendants, rings and fragments of weapons.
He believes that today’s Staraya Maina, a town of eight thousand, was ten times more populated in the ancient times. It is from here that people started moving to the Don and Dneiper rivers around the time ancient Russy built the city of Kiev, now the capital of Ukraine.
An international conference is being organised later this year to study the legacy of the ancient village, which can radically change the history of ancient Russia.
http://www.mosnews.com/news/2007/01/04/harevishnu.shtml