Short answers, pulled from the story.
Manuel Chrysoloras was a Byzantine Greek scholar, humanist, diplomat, and professor born in Constantinople around 1350, who died on the 15th of April 1415. He is widely regarded as a pioneer in bringing ancient Greek literature to Western Europe, having taught Greek in Florence, Bologna, Venice, and Rome during the late fourteenth and early fifteenth centuries.
Chrysoloras initially traveled to Venice in 1390 as an ambassador for the Byzantine emperor Manuel II Palaiologos, seeking military assistance from Christian rulers in Western Europe against Ottoman Turkish incursions on the Byzantine Empire. This diplomatic visit led to scholarly contacts that eventually resulted in his invitation to teach in Florence.
Chrysoloras taught Greek grammar and literature in Florence from 1397 to 1400, beginning with the rudiments of the language. His students included Leonardo Bruni, Guarino da Verona, Niccolò de' Niccoli, Carlo Marsuppini, Pier Paolo Vergerio, Palla Strozzi, and others who became leading figures of the Italian Renaissance.
The Erotemata is a Greek grammar textbook written by Chrysoloras, recognized as the first basic Greek grammar in use in Western Europe. It was first published in 1484 and widely reprinted; Thomas Linacre studied it at Oxford and Desiderius Erasmus studied it at Cambridge.
Chrysoloras translated the works of Homer, Aristotle, and Plato's Republic into Latin, making these texts accessible to western scholars who lacked direct knowledge of ancient Greek.
Chrysoloras died suddenly on the 15th of April 1415, while traveling to the church council at Constance, an assembly he had helped arrange through his embassy to the Holy Roman Emperor Sigismund in 1413. He had been chosen to represent the Greek Church at the council but did not live to participate.