Constantine Lascaris was born in Constantinople, where he was educated by the scholar John Argyropoulos, Gemistus Pletho's friend and pupil.
After the fall of Constantinople in 1453, he took refuge in Rhodes and then in Italy, where Francesco Sforza, Duke of Milan, appointed him Greek tutor to his daughter Hippolyta.
Here was published his Grammatica Graeca, sive compendium octo orationis partium, remarkable as being probably the first book entirely in Greek issued from the printing press, in 1476.
He continued to work in Messina until his death, teaching many pupils who came on purpose to Sicily, from all over Italy, to learn grammar and Greek culture from him.
The Grammatica, which has often been reprinted (including the famous Manuzio's edition of 1494–1495 with the Golden Verses of Pythagoras), is the most valuable work produced by Lascaris.