The years between 1917 and 1930 form the first period

Legacy...Rowling's Harry Potter series has been credited with a resurgence in crossover fiction: children's literature with an adult appeal.Crossovers were prevalent in 19th-century American and British fiction, but fell out of favour in the 20th century and did not occur at the same scale. The post-Harry Potter crossover trend is associated with the fantasy genre.In the 1970s, children's books were generally realistic as opposed to fantastic, while adult fantasy became popular because of the influence of The Lord of the Rings. The next decade saw an increasing interest in grim, realist themes, with an outflow of fantasy readers and writers to adult works.The commercial success of Harry Potter in 1997 reversed this trend.The scale of its growth had no precedent in the children's market: within four years, it occupied 28% of that field by revenue.Children's literature rose in cultural status,and fantasy became a dominant genre.Older works of children's fantasy, including Diana Wynne Jones's Chrestomanci series and Diane Duane's Young Wizards, were reprinted and rose in popularity; some authors re-established their careersIn the following decades, many Harry Potter imitators and subversive responses grew popular.Rowling has been compared to Enid Blyton, who also wrote in simple language about groups of children and long held sway over the British children's market.She has also been described as an heir to Roald Dahl. Some critics view Harry Potter's rise, along with the concurrent success of Philip Pullman's His Dark Materials, as part of a broader shift in reading tastes: a rejection of literary fiction in favour of plot and adventure.This is reflected in the BBC's 2003 "Big Read" survey of the UK's favourite books, where Pullman and Rowling ranked at numbers 3 and 5, respectively, with very few British literary classics in the top 10.
Harry Potter's popularity led its publishers to plan elaborate releases and spawned a textual afterlife among fans and forgers. Beginning with the release of Prisoner of Azkaban on 8 July 1999 at 3:45 pm,its publishers coordinated selling the books at the same time globally, introduced security protocols to prevent premature purchases, and required booksellers to agree not to sell copies before the appointed time.Driven by the growth of internet access and use around its initial publication, fan fiction about the series proliferated and has spawned a diverse community of readers and writers. While Rowling has supported fan fiction, her statements about characters – for instance, that Harry and Hermione could have been a couple, and that Dumbledore was gay – have complicated her relationship with readers. According to scholars, this shows that modern readers feel a sense of ownership over the text that is independent .