Korolev grew up in Nizhyn, under the care of his maternal grandparents Mykola Yakovych Moskalenko who was a trader of the Second Guild and Maria Matviivna Moskalenko (Fursa), a daughter of a local cossack. Korolev's mother also had a sister Anna and two brothers Yuri and Vasyl. Maria Koroleva was frequently away attending Women's higher education courses in Kyiv. As a child, Korolev was stubborn, persistent, and argumentative. Sergei grew up a lonely child with few friends. Korolev began reading at an early age, and his abilities in mathematics and other subjects made him a favorite student of his teachers, but caused jealousy from his peers. He later stated in an interview, the torment of classmates bullying and teasing him as a small child encouraged his focus on academic work. His mother divorced Pavel in 1915 and in 1916 married Grigory Mikhailovich Balanin, an electrical engineer who had been educated in Germany but who had to attend the Kiev Polytechnic University because German engineering diplomas were not recognized in Russia. After getting a job with the regional railway, Grigory moved the family to Odessa in 1917, where they endured hardships with many other families through the tumultuous years following the Russian Revolution and continuing internecine struggles until the Bolsheviks assumed unchallenged power in 1920. Local schools were closed and young Korolev had to continue his studies at home. Grigory proved a good influence on his step-son, who suffered from a bout of typhus during the severe food shortages of 1919.