A son of the Gupta king Chandragupta II and Queen Dhruvadevi, he seems to have maintained control of his inherited territory, which extended from Gujarat in the west to Bengal region in the east.

The Bhitari pillar inscription states that his successor Skandagupta restored the fallen fortunes of the Gupta family, which has led to suggestions that during his last years, Kumaragupta suffered reverses, possibly against the Pushyamitras or the Hunas.

[5] He also adopted the title Mahendraditya, and his coins call him by several variants of this name, including Shri-Mahendra, Mahendra-simha, and Ashvamedha-Mahendra.

[7] Kumaragupta had inherited a large empire built upon the conquests of his father Chandragupta II and his grandfather Samudragupta.

[8] Thus, even if his reign was militarily uneventful, he must have been a strong ruler for being able to maintain a stable government in a large empire, as indicated by epigraphic and numismatic evidence.

For example, he worshipped the war god Karttikeya, and his gold coins suggest that he performed the Ashvamedha ceremony which was used by ancient kings to prove their sovereignty.

Bandhuvarman's grandfather Naravarman and his father Vishvavarman seem to have been independent rulers, because none of the three inscriptions issued during their reigns refer to a Gupta overlord.

Majumdar theorizes that the Dashapura region was annexed to the Gupta empire during the reign of Kumaragupta I, either through military conquest or diplomacy.

Another category of his coins portray him as a tiger-slayer, which according to historian H. C. Raychaudhuri, may allude to his incursions of the territory to the south of the Narmada River, where tigers are abundant.

[15] Epigraphic evidence suggests that Kumaragupta ruled his empire through governors (Uparikas), who bore the title Maharaja ("great king"), and administered various provinces (Bhuktis).

His c. 435-436 inscription suggests that he was a member of the Gupta royal family, probably a son or younger brother of Kumaragupta.

[18] The 436 CE Karamdanda inscription mentions Prithivishena, who was initially mantrin and kumaramatya (minister) of Kumaragupta I, and later became his mahabaladhikrita (general).

[20] Kumaragupta seems to have established diplomatic relations with the Liu Sung emperors of China, as suggested by visits of Chinese delegations to India, and the exchange of an Indian envoy.

[5] As mentioned above, Ghatotkacha-gupta (not to be confused with the earlier king Ghatotkacha) was probably a son or younger brother of Kumaragupta.

[14] The Chinese traveler Xuanzang mentions Budhagupta after king Shakraditya (identified as Kumaragupta I by some scholars) while naming the patrons of the Nalanda monastery.

[23] Epigraphic evidence indicates that various faiths including Shaivism, Vaishnavism, Buddhism, and Jainism, flourished during Kumaragupta's reign.

This theory is based on the Junagadh inscription which suggests that Skandagupta defeated the mlechchhas (foreigners, possibly the Hunas) before c. 455 CE.

It is also possible that both of these theories are true: Skandagupta may have been dispatched to the frontier to check a Huna invasion; meanwhile, Kumaragupta died in the capital, leading to a succession dispute.