A minor line of the Gupta clan continued to rule Magadha after the disintegration of the empire. These Guptas were ultimately ousted by the king Harshavardhana, who established an empire in the first half of the seventh century that, for a brief time, rivalled that of the Guptas in extent.
From around the middle of the sixth century A.D. till about 675 A.D., the kings who ruled Magadha were known as Magadha Guptas or Later Guptas. However, it is not clear what connection they had with the Imperial Guptas of the earlier period. The Aphsad inscription from Gaya gives the names of 8 Gupta Monarchs; Krishnagupta, Harshagupta, Jivitagupta I, Kumaragupta III, Damodaragupta, Mahasenagupta, Madhavagupta and Adityasena.
The Later Guptas entered into matrimonial alliances with other contemporary ruling families. For example. Harshagupta married his sister to a Maukhari king.
Throughout this period the Later Guptas remained engaged in battle with one enemy or the other. For esample, Harshagupta had to fight the Hunas; his son Jivitagupta fought against the Lichchhavis of Nepaland and the Gaudas of Bengal; and Jivitagupta’s successor Kumaragupta III defeated the Maukhari King Isanavarman.
The next king Damodaragupta, son of Kumaragupta III, was defeated and killed by the Maukhari king Sarvavarman and lost a portion of Magadha.
For some time the successors of Damodaragupta retreated to Malwa because of the Maukharis but they again established their supremacy in Magadha.
Their most powerful ruler was Adityasena, who ruled in Magadha in 672 A.D., a date which seems to occur in one of his inscriptions.
The Later Gupta power survived the empire of Harshavardhana, and Adityasena signalised his accession to power by the performance of a horse sacrifice.
According to the Aphsad inscription, his empire included the provinces of Magadha, Anga and Bengal. It is just possible that his kingdom included a portion of present-eastern Uttar Pradesh. He was a Parama-Bhagavata and got a temple of Vishnu constructed.
The Later Gupta line came to an end with the expansion of the power of the Gaudas of Bengal westward. But the Gaudas themselves were subdued by Yasovarman of Kanauj.
The Maukharis belong to a very ancient family. A clay seal of the Maukharis has been found at Gaya belonged to the Maurya period. Reference to a Maukhari general is found in an inscription dated 239 A.D., discovered at Kotah in Rajputana.
Four stone inscriptions of different Maukhari families have been in this area, which indicate existence of seven Maukhari families during the third century. The Maukharis claimed descent from Asvapati, mentioned in the Mahabharata as the King of Madra in the Central Punjab.
From epigraphic evidence we come to know that two groups of Maukhari Kings ruling in South Bihar and U.P. early in the sixth century A.D. The founder of one group of rulers was Yajnavarman who was succeeded by his son Sardulavarman and Anantavarman. The rulers of the second group were Harivarman. Adityavarman, Ishwaravarman, Ishanavarman, Sarvavarman, Avantivarman, and Grahavarman; who were feudatories to the Guptas and ruled early in the sixth century A.D. They are referred to as Samantas or Samantachudamani.
Harivarman, the first of the second line of rulers, assumed the title of Maharaja and it is presumed that he perhaps had assumed an independent status. He is described in his inscriptions as one who had carried on extensive military campaigns and brought other kings under subjection.
The Maukhari history becomes definite from, the time of Ishanavarman. One of his inscriptions dated A.D. 554 coincides with the downfall of the Gupta Empire and he must have come to power before this date. Ishanavarman claims to have defeated the Andhras, Sulikas and the Gaudas, and assumed the title of Maharajadhiraja.
It is, therefore, probable that Ishanavarman was the first full-fledged independent Maukhari king. It is, however, not possible to determine the limits of his dominions with certainty. From the findspots of his coins it is presumed to be present Uttar Pradesh, parts of Orissa, and Bengal.
The later Gupta rulers had protracted conflict with the Maukharis and King Ishanavarman was defeated by Kumaragupta and probably also by Damodargupta. Ishanavarman was succeeded by Sarvavarman and the latter by Avantivarman.
From Bana’s Harshacharit we come to know that Avantivarman was succeeded by his son Grahavarman who later married Rajyasri, daughter of Prabhakarvardhana, the Pushyabhuti king of Thaneswar. Grahavarman was not, however, destined to rule for long. Devagupta, a Gupta king of Malwa, who was an ally of King Sasanka of Gauda, defeated and killed Grahavarman and carried away Rajyasri as captive.
Rajyavardhana was also killed by Sasanka, ally of Devagupta and the throne of Thaneswar also fell vacant. It was at this juncture, that the throne of Kanauj, i.e. of the Maukharis, was united with that of Thaneswar, and Harshavardhana became the king of the United Kingdom.