Green had been a student at Oxford in the 1930’s (where Lewis taught) and while he was not tutored by Lewis, he did attend some of his public lectures. Fans of Lewis likely know him best for his 1974 biography C.S. Lewis: A Biography coauthored with Walter Hooper. However, as noted above, he was known to others for his children’s books, many that were retellings of known stories (King Arthur and His Knights of the Round Table being another).
On that faithful day in March, 1949 Green expressed great praise to the eventual masterpiece and this likely gave Lewis the encouragement he needed because he finished the book by the end of the month. Green ultimately got to read all the other stories as they were written (which is different than the published and chronological order). In fact, in Teller of Tales Green covers The Chronicles of Narnia in the order he read them. One final interesting fact about Green is that he was the one who suggested the name of the Narnia series that we currently use.
You can learn other interesting information about what happen in C.S. Lewis’s life week by week in a series featured at EssentialCSLewis.com.