C. S. Lewis based the protagonist of his ‘space trilogy’ on Tolkien

When they both worked as professors at the University of Oxford, the two men were close friends for many years. Curiously, although being well-known for their involvement in the Inklings reading club, they were also a part of the Coalbiters in the 1920s, a society created particularly to debate Icelandic literature and myth. When Lewis wrote his science fiction books, starting with Out of the Silent Planet in 1938, where the protagonist, Elwin Ransom, is a philologist, he relied on their connection just as Tolkien was. The work of the other man was criticized by the other man. Lewis noted in his notebook about Tolkien just after their first encounter: "No harm in him merely needs a whack or so."

Beyond the fact that Tolkien disliked Lewis' Narnia books (because of their allegory, of course) and that Lewis was a Protestant while Tolkien was a Roman Catholic, there are other distinctions between the two authors. Lewis was a charismatic public speaker who popularized medieval literature, but Tolkien was universally regarded as a horrible lecturer. Kingsley Amis called him "incoherent and sometimes inaudible," and Douglas Gray called him "one of the world's worst lecturers." Lewis showed little interest in textual editing, in contrast to Tolkien's meticulous and even obsessive fixation with the finer points of academic annotation. Tolkien preferred to revise medieval manuscripts rather than produce many academic books. Additionally, he detested allegory since it reduced a work's meaning to a straightforward x = y paradigm. Lewis, on the other hand, offered us The Allegory of Love.

Despite these early problems, Lewis occasionally supported the writing of his buddy and eventually suggested Tolkien for the Nobel Prize in Literature. Tolkien was denied the Nobel Prize because, in their words, his writing "had not in any way matched up to the narrative of the highest quality."