The request for a sequel prompted Tolkien to begin what would become his most famous work: the epic novel The Lord of the Rings (originally published in three volumes 1954–1955). Tolkien spent more than ten years writing the primary narrative and appendices for The Lord of the Rings, during which time he received the constant support of the Inklings, in particular his closest friend Lewis, the author of The Chronicles of Narnia. Both The Hobbit and The Lord of the Rings are set against the background of The Silmarillion, but in a time long after it.
Tolkien at first intended The Lord of the Rings to be a children's tale in the style of The Hobbit, but it quickly grew darker and more serious in the writing.[150] Though a direct sequel to The Hobbit, it addressed an older audience, drawing on the immense backstory of Beleriand that Tolkien had constructed in previous years, and which eventually saw posthumous publication in The Silmarillion and other volumes. Tolkien's influence weighs heavily on the fantasy genre that grew up after the success of The Lord of the Rings.
The Lord of the Rings became immensely popular in the 1960s and has remained so ever since, ranking as one of the most popular works of fiction of the 20th century, judged by both sales and reader surveys.[151] In the 2003 "Big Read" survey conducted by the BBC, The Lord of the Rings was found to be the UK's "Best-loved Novel".[152] Australians voted The Lord of the Rings "My Favourite Book" in a 2004 survey conducted by the Australian ABC.[153] In a 1999 poll of Amazon.com customers, The Lord of the Rings was judged to be their favourite "book of the millennium".[154] In 2002 Tolkien was voted the 92nd "greatest Briton" in a poll conducted by the BBC, and in 2004 he was voted 35th in the SABC3's Great South Africans, the only person to appear in both lists. His popularity is not limited to the English-speaking world: in a 2004 poll inspired by the UK's "Big Read" survey, about 250,000 Germans found The Lord of the Rings to be their favourite work of literature