among them Dmitry Semyonovsky, Vasily Nasedkin, Nikolai Kolokolov and Ivan Filipchenko. Yesenin’s first marriage (which lasted three years) was in 1913 to Anna Izryadnova, a co-worker from the publishing house, with whom he had a son, Yuri. 1913 saw Yesenin becoming increasingly interested in Christianity, biblical motives became frequent in his poems. "Grisha, what I am reading at the moment is the Gospel and find a lot of things which for me are new," he wrote to his close childhood friend G. Panfilov. That was also the year when he became involved with the Moscow revolutionary circles: for several months his flat was under secret police surveillance and in September 1913 it was raided and searched. Life and career January 1914, Yesenin's first published poem "Beryoza" (The Birch Tree) appeared in the children's magazine Mirok (Small World). More appearances followed in minor magazines such as Protalinka and Mlechny Put. In December 1914 Yesenin quit work "and gave himself to poetry, writing continually," according to his wife. Around this time he became a member of the Surikov Literary and Music circle. In 1915, exasperated with the lack of interest in Moscow, Yesenin moved to Petrograd. He arrived to Petrograd on 8 March and the next day met Alexander Blok at his home, to read him poetry. He was quickly acquainted with fellow-poets Sergey Gorodetsky, Nikolai Klyuev and Andrei Bely who were well known. Blok was especially helpful in promoting Yesenin's early literary career, describing him as "a gem of a peasant poet" and his verse as "fresh, pure and resounding", even if "wordy". The same year he joined the Krasa (Beauty) group of peasant poets which included Klyuyev, Gorodetsky, Sergey Klychkov and Alexander Shiryayevets, among others. In his 1925 autobiography Yesenin said that Bely gave him the meaning of form while Blok and Klyuev taught him lyricism. It was Klyuyev who introduced Yesenin to the publisher Averyanov, who in early 1916 released his debut poetry collection Radunitsa which featured many of his early spiritual-themed verse. "I would have eagerly relinquished some of my religious poems, large and small, but they make sense as an illustration of poets' progress towards the revolution," he would later write. Yesenin and Klyuyev maintained close and intimate friendship which lasted several years. Later in 1915, Yesenin became a co-founder of the Krasa literary group and published numerous poems in the Petrograd magazines Russkaya Mysl, Ezhemesyachny Zhurnal,