Kālidāsa
The most popular theory is that Kalidasa flourished during the reign of Chandragupta II, and therefore lived around 4th-5th century CE. Several Western scholars have supported this theory, since the days of William Jones and A. B. Keith. Many Indian scholars, such as Vasudev Vishnu Mirashi and Ram Gupta, also place Kalidasa in this period. According to this theory, his career might have extended to the reign of Kumaragupta I (r. 414 – 455 CE), and possibly, to that of Skandagupta (r. 455 – 467 CE).
Buddhadatta
Buddhadatta Thera was a 5th-century Theravada Buddhist writer from the town of Uragapura in the Chola kingdom of South India. He wrote many of his works in the Bhūtamangalagāma monastery and his patron was Accutavikkanta of the Kambala dynasty. Buddhadatta traveled to Sri Lanka's Mahāvihāra in Anurādhapura to study and translate the commentaries on the Buddha's teachings from Sinhalese to Pali. He is said to have met Buddhagosa at sea while returning to India, his work unfinished. Buddhadatta asked Buddhagosa to send him his translations and commentaries and used them in the writing of his Abhidhammāvatāra. The Abhidhammāvatāra (Pali: “The Coming of the Abhidhamma”) is one of the earliest and most important Abhidhamma manuals. It is a systematized overview of the doctrines in the Abhidhamma Pitaka, written largely in 24 verse chapters. Buddhadatta's other works include the Vinaya-Vinicchaya (“Analysis of the Vinaya”), the Uttara-Vinicchaya, the Rūpārūpa-Vibhāga.