Held every year for almost half a century, it would be criminal to write about world book fairs without mentioning London. The London Book Fair grew out of a specialist event for librarians, which was originally intended to provide a platform for small publishers to exhibit their work. These days, the London Book Fair is a massive international affair and, in Europe at least, it’s second only to Frankfurt. After moving location a few times, the fair has been held in Olympia for the last couple of years.