According to Hultzsch, Vallabhadeva, hailing from Kashmir, represents the oldest known commentary on the Meghadūta. He also wrote commentaries on two other of Kālidāsa ‘s poems: Raghuvrāṁsa and Kumrasaṁbhaba, as well as commentaries on other works. Vallabhadeva ;s commentary is thought to be the earliest surviving commentary, at around 1000 A.D, on the poem, and hence approximately dates Kālidāsa as well. Evidence of this dates rests on the knowledge that Vallabhadeva’s apparent grandson Kayyata, son of Chandrāditya wrote a commentary on Ānadavardhana’s Devīśataka around 977/8. According to Hultzsch’s sources Vallabhadeva’s father was a high ranking military man in Kshmir. Vallabhadeva’s other commentaries all refer back to works and authors belonging to the time before 900AD, hence confirms his approximate existence in time. Dr. De’s article on “Some Commentators On The Meghaduta” available at http://www.wilbourhall.org/sansknet/jyotisha/papers_on_jyothisa/Meghaduta.htm provides further information on other commentators, including Bengal and West Indian commentators. What I personally find astonishing is how little is known about this person Vallabhadeva, really nothing has survived apart from his commentaries and some scant information about his lineage. Very sobering.
Cloud of a cloud