He was the translator of Ariosto's Orlando Furioso producing an abridgment in twelve cantos in 1590 preceding Sir John Harington's translation the following year. The translation appeared with some of his own poems in a volume bearing the title Ane Abbregement of Roland Fvriovs, translait ovt of Aroist: togither vith sym Rapsodies of the Avthor's ycvthfvll braine, and last ane Schersing ovt of trees Felicitie; composit in Scotis a copy of which is preserved in the Advocates' Library, Edinburgh.
This may well have been the 'propyne' of verse which Stewart gave to James VI as a new year present in 1584. Stewart wrote of the king deserving a "doubill croune and moir", not just referring to the likelihood of James inheriting the English throne, but also to coronation of Petrarch as poet-king in Rome in 1341, or that of Conrad Celtis in 1487Court, Kirk, and Community: Scotland, 1470-1625 by Jenny Wormald (p. 186).
Donna C. Heddle, John Stewart of Baldynneis Roland Furious: A Scots Poem in its European Context (Leiden, Brill, 2007) (Brill's Studies in Intellectual History, 158).