From the Wikipedia page 
He was the son of John d'Argentine, of Great Wymondley. The Argentines had been settled in Cambridgeshire since the Norman conquest of England. He was educated at Eton and King's College, Cambridge.
A doctor, trained in Strasbourg, Argentine was the last attendant of the Princes in the Tower. He fled England after the Coronation of King Richard III and became one of the possible sources for Dominic Mancini's report that the young King Edward V was daily in fear of his life.
Argentine's evidence was also the basis for French declarations that the Princes in the Tower of London had been murdered and their assassin crowned as King Richard III.
Later he became physician to Prince Arthur. He ended his life as Provost of King's College, Cambridge and is buried there in the Chantry Chapel.