Nalanda's datable history begins under the Gupta Empire and a seal identifies a monarch named Shakraditya as its founder. Both Xuanzang and a Korean pilgrim named Prajnyavarman attribute the foundation of a sangharama (monastery) at the site to him. Shakraditya is identified with the 5th-century CE Gupta emperor, Kumaragupta I (r.c. 415 - c. 455 CE), whose coin has been discovered at Nalanda. His successors, Buddhagupta, Tathagatagupta, Baladitya, and Vajra, later extended and expanded the institution by building additional monasteries and temples.
The Guptas were traditionally a Brahmanical dynasty. Narasimhagupta (Baladitya) however, was brought up under the influence of the Mahayanist philosopher, Vasubandhu. He built a sangharama at Nalanda and also a 300 ft (91 m) high vihara with a Buddha statue within which, according to Xuanzang, resembled the "great Vihara built under the Bodhi tree". The Chinese monk also noted that Baladitya's son, Vajra, who commissioned a sangharama as well, "possessed a heart firm in faith".