Russian literature refers to the literature of Russia and its émigrés and to the Russian-language literature of several independent nations once a part of what was historically Rus', Russian Empire or the Soviet Union. Roots of Russian literature can be traced to the Middle Ages, when epics and chronicles in Old Russian were composed. By the Age of Enlightenment, literature had grown in importance, and from the early 1830s, Russian literature underwent an astounding golden age in poetry, prose and drama. Romanticism permitted a flowering of poetic talent: Vasily Zhukovsky and later his protégé Alexander Pushkin came to the fore. Prose was flourishing as well. The first great Russian novelist was Nikolai Gogol. Then came Ivan Turgenev, who mastered both short stories and novels. Leo Tolstoy and Fyodor Dostoyevsky soon became internationally renowned. In the second half of the century Anton Chekhov excelled in short stories and became a leading dramatist. The beginning of the 20th century ranks as the Silver Age of Russian poetry. The poets most often associated with the "Silver Age" are Konstantin Balmont, Valery Bryusov, Alexander Blok, Anna Akhmatova, Nikolay Gumilyov, Osip Mandelstam, Sergei Yesenin, Vladimir Mayakovsky, Marina Tsvetaeva and Boris Pasternak. This era produced some first-rate novelists and short-story writers, such as Aleksandr Kuprin, Nobel Prize winner Ivan Bunin, Leonid Andreyev, Fedor Sologub, Aleksey Remizov, Yevgeny Zamyatin, Dmitry Merezhkovsky and Andrei Bely. After the Revolution of 1917, Russian literature split into Soviet and white émigré parts. While the Soviet Union assured universal literacy and a highly developed book printing industry, it also enforced ideological censorship. In the 1930s Socialist realism became the predominant trend in Russia. Its leading figure was Maxim Gorky, who laid the foundations of this style. Nikolay Ostrovsky's novel How the Steel Was Tempered has been among the most successful works of Russian literature. Alexander Fadeyev achieved success in Russia. Various émigré writers, such as poets Vladislav Khodasevich, Georgy Ivanov and Vyacheslav Ivanov; novelists such as Mark Aldanov, Gaito Gazdanov and Vladimir Nabokov; and short story Nobel Prize winning writer Ivan Bunin, continued to write in exile. The Khrushchev Thaw brought some fresh wind to literature and poetry became a mass cultural phenomenon. This "thaw" did not last long; in the 1970s, some of the most prominent authors were banned from publishing and prosecuted for their anti-Soviet sentiments. The end of the 20th century was a difficult period for Russian literature, with few distinct voices. Among the most discussed authors of this period were Victor Pelevin, who gained popularity with short stories and novels, novelist and playwright Vladimir Sorokin, and the poet Dmitry Prigov. In the 21st century, a new generation of Russian authors appeared, differing greatly from the postmodernist Russian prose of the late 20th century, which lead critics to speak about “new realism”. Leading "new realists" include Ilja Stogoff, Zakhar Prilepin, Alexander Karasyov, Arkadi Babchenko, Vladimir Lorchenkov, Alexander Snegiryov and the political author Sergej Shargunov. Russian authors significantly contributed almost to all known genres of the literature. Russia had five Nobel Prize in literature laureates. As of 2011, Russia was the fourth largest book producer in the world in terms of published titles. A popular folk saying claims Russians are "the world's most reading nation".