J.R.R. Tolkien(1892-1973)

Tolkien's mother introduced him to Latin, French, and German. While at school (mostly at Oxford) he was taught or taught himself Greek, Middle English, Old English (also called Anglo Saxon), Old Norse (also called Old Icelandic), Gothic, Modern and medieval Welsh, Finnish, Spanish, and Italian. Other languages of which he had a working knowledge include Serbian, Russian, Swedish, Danish, Norwegian, Dutch, and Lombardic. In addition to these languages, Tolkien invented 14 different languages and assorted alphabets for his Middle-earth dwellers.

"American English is essentially English after having been wiped off with a dirty sponge." - from a letter in 1953 to Robert Murray, a Jesuit priest, in the book, 'The Letters of J.R.R. Tolkien' (1981)