The political scenario of northern India after the extinction of the Kushanas and the Andhras till the ascendancy of the imperial Guptas was absolutely anarchic and tumultuous. This period was one of the darkest periods in Indian history and the historians have ascribed the term "Dark Age" to this period. The epoch of the Dark Age, i.e. the beginning of the 4th century, the existing power-Kushanas could not retain the administrative machinery of their Empire properly. As a result incessant local revolts started occurring. The provincial and local governors took the advantage of the weakness of the central authority and demanded their independence. They raised their standard of revolt against the Kushana yoke and established their own independent kingdom. The weakness of the central authority made the situation pregnant enough for internal discords and anarchy and India was wrapped in petty political atoms. The states which unfurled the flag of their independence, after getting detached from the folds of central authority of the Kushanas, established their independent status either as monarchic states or as republican states. However history of the "Dark Age" began from the Kushana period, when forces of disintegration crept up during the later Kushanas.

Calling the intervening period between the decline of the Kushanas and the ascendancy of the Guptas as Dark Age however is a point of keen debate. Many scholars still believe that the Kushana age was a prelude to Gupta imperialism and Gupta Renaissance. According to them there was no certain break of continuity between the Kushana traditions, which was handed down to the Guptas. Later modern interpreters have pointed out that there was almost a gap of one and a half century between the Kushana Age and the Gupta era. Kushana Empire was utterly disintegrated before the ascendancy of the Guptas. According to historians there was no glorious history of the period and the period can be truly be called the "Dark Age".

With the breakdown of the Kushana administration, the Empire was disintegrated into several small provincial independent states. According to historians, the disintegration of the Kushana Empire started from the eastern part of their territory. The entire eastern dominion was crumbled into several monarchic states, where the provincial governors established independent states of their own.

In the Gangetic Valley the earliest power to detach itself from the Kushana yoke and to establish an independent ruling line in Kausambhi were the Maghas. The Maghas rose in power about 130 A.D., under the leadership of Maharaja Bhimasena. He carved out a vast and strong kingdom in Kausambhi of Uttar Pradesh and was succeeded by his son Kautsiputra Pothasiri. The next important ruler of the Magha lineage was Bhadra Magha. He also extended his sway beyond the region of Kausambhi.The last Magha ruler of Kausambhi was Rudra, who appears to be Rudradeva of the Allahabad Pillar inscription, and was later defeated by Samudragupta.

In third century A.D., the Ayodhya region of eastern U.P. was occupied by a group of rulers, whose names ended with the titles "Mitra". The names like Satya Mitra, Ayu Mitra, Sangha Mitra, and Vijay Mitra etc. were prevalent among these tribes. The "Mitra" tribes wrested power from one of the Kushana successors and established their own supremacy. But according to Dr. S.Chattopadhya, this region was ruled by the Saka-Murandas, who extended their sway upto Magadha. The theory of Dr. Chattopadhya was also corroborated by the Puranas. According to the Puranas, a Saka ruler named Visvaphani ruled Magadha before the ascendancy of the Guptas.

While the Gangetic valley was under the authority of the "Mitra" rulers or the Saka Murandas, the Yamuna valley passed under the rule of the Naga kings. The Nagas were the serpent worshipping, non-Aryan tribes in ancient India. Overthrowing the Kushanas from the regions of Mathura and Vidisha, they acquired immense power and prestige in those regions. After the fall of the Kushanas, the Nagas formed a formidable Empire of their own in Northern India. According to Puranas, Vidisha, Kantipuri, Mathura and Padmavati formed the four important strongholds of the Naga Power. The Puranas stated that, when the Guptas were rising to power, there were seven Naga kings ruling in Mathura and nine Naga kings in Padmavati. Though the names of those Naga kings have not yet been discovered, from epigraphic and the literary evidences it is clear that the Nagas held their sway over a considerable portion of Northern India.

Among the Naga rulers only the name of Bhavanaga of Padmavati is mentioned in the Vakataka records. It is generally believed that the daughter of Bhavanaga, the Naga princess was married to the Vakataka prince. Bhavanaga was a powerful king who had performed ten horse sacrifices and extended his conquests upto the Ganges. Bhavanaga was a worshipper of Lord Shiva and his family came to be known as the Bharasivas. It has been pointed out by historians that the successors of king Bhavanaga had extended their authority upto Mathura from the Padmavati region. Bhavanaga was probably succeeded by Nagasena and later by Ganapatinaga. The Allahabad Prasasti of Samudragupta stated that Samudragupta had uprooted two Naga kings-- Nagasena and Ganapatinaga, who have been identified as the successors of Bhavanaga by historians. Furthermore the coins of Ganapatinaga were found in Padmavati.

K.P. Jaiswal, one of the famous interpreters of ancient history has pointed out that the Bharasiva Nagas of Padmavati led a war of liberation against the foreign Kushanas and finally became an imperial power by stretching their sway over the whole of Northern India and parts of Deccan. The early Guptas, Vakatakas and many republican tribes were feudatories of the Nagas. But the theory of the Nagas is discarded by most of the scholars due to the fact that it was not supported by enough evidence. According to them, not the Nagas, rather the Sassanians were master of the entire North India after the downfall of the Kushanas. However as far as indigenous literary records suggest, many Naga kings had ruled over various parts of India in 3rd and in early 4th century A.D. The Allahabad Pillar inscription of Samudragupta refers to the Naga kings, who were at the helm of power in Northern India before the Gupta ascendancy. The Allahabad Prasasti also depicted that the founder king of the Gupta Dynasty, Chandragupta II had established friendly relations with the Nagas and also had married a Naga princess. Skandagupta had appointed a Naga chief as his provincial Governor. From these evidences it becomes clear that the Nagas were the principal authority who had ruled India before the arrival of the Guptas.

While the Kushana Empire in the Ganga-Yamuna Valley was almost crumbled, several small local royal houses came into power, who had formed independent republican states of their own. They overthrew the Kushana supremacy in the regions of Rajputana and Punjab. The Yaudheyas populated Eastern Punjab, Northern Punjab and the adjoining parts of Uttar Pradesh. Yaudheyas were warrior tribes who had the passion for freedom. They formed their own republican state, after ousting the Kushanas. They worshipped Brahmanyadeva or the first Pandava, Yudhisthira. They were defeated bay
Mahakshatrapa Rudramana before with the assistance of the Kushanas, but they however managed to liberate themselves from the shackles of the Kushanas about 175 A.D. and issued some commemorative coins in order to celebrate their victory. Maharaja was the republican head of the Yaudheyas. Some scholars also link the Jats of Bharatpur with the warrior tribes-Yaudheyas.

Arjunayas were the other republican tribes, who concentrated in the regions of Bharatpur and Alwar state of Rajputana. These tribes claimed their descent from the second Pandava, Arjuna. The Arjunayas were subdued by the Sakas and were compelled to offer their allegiance to the Kushanas, who were the central authority of the entire northern India in second century. Arjunayas asserted their independence during the decline of the Kushana power in the centre. They were republican tribes, who had established a kingdom of their own, but their liberty was a short-lived one and by the middle of fourth century A.D., they were conquered by the Guptas.

Malavas were another bunch of a significant republican tribe, who originally concentrated in the region of Punjab during Alexander`s invasion. But in fourth century A.D., the succeeding Malavas migrated to Rajputana, yielding under pressure of the Saka invasion. Malavanagara in Jaipur state was the capital of the Malavas. After the downfall of the Kushanas, they asserted their independence and extended their sway in different directions and also issued coins in order to celebrate their victory. They had bitter rivalry with the Kardamaka Sakas. The Malavas followed the Krita era. Ultimately they were subjugated by the Guptas.

Apart from these, there were several others republican tribes like the Licchavis, the Sanakanikas, the Kakas etc. Among them the Licchavis later offered allegiance to the Guptas and allied with Chandragupta I in matrimonial relation. Nothing is known about the other republican tribes.

However the period between the downfall of the valiant Kushanas and the ascendancy of the Imperial Guptas, was a period of anarchy and chaos. The entire north India was broken into small provinces, which were continuously engaged in strife with one another. Hence the historians termed the period as the "Dark Age". In 4th century A.D. when the Guptas came in power, they first consolidated the entire north India under their own supremacy and after that established their own Empire in 4th century A.D.