In 1995 W. A. Meeuws, Managing Director of Thornton’s bookstore in Oxford, thoughtfully sent me a list of all the books by Lewis that had been translated into foreign languages, including the publisher, location, date, number of pages, and binding. The list included 168 books in 23 languages ranging from Afrikans to Swedish.
The language with the most Lewis books was German, with a total of 26; and the runner-up was Spanish, with 23. There were 17 Lewis books in Norwegian, 14 in Finnish, 12 in Dutch, and 12 in Italian. The only languages limited to one book by Lewis were Afrikans, Slovak, and Slovenian. Their respective titles were Mere Christianity, The Problem of Pain, and Mere Christianity.
The 1999 issue of Seven includes a past interview of Harry Blamires in which he recalls Lewis showing him the picture of Aslan in a French Narnia book. But the Thornton’s list includes no French Narnia books; apparently it is incomplete.
For a copy of the list, send a SASE.