Context: Russia, also officially known as the Russian Empire, was a state that existed from 1721 until it was overthrown by the short-lived liberal February Revolution in 1917. One of the largest empires in world history, stretching over three continents, the Russian Empire was surpassed in landmass only by the British and Mongol empires. The rise of the Russian Empire happened in association with the decline of neighboring rival powers: the Swedish Empire, the PolishLithuanian Commonwealth, Persia and the Ottoman Empire. It played a major role in 181214 in defeating Napoleon's ambitions to control Europe, and expanded to the west and south., Grigori Yefimovich Rasputin was a Russian peasant, an experienced traveler, a mystical faith healer, and trusted friend of the family of Nicholas II, the last Tsar of the Russian Empire. He became an influential figure in Saint Petersburg, especially after August 1915 when Nicholas took command of the army fighting in World War I. Advising his wife, Alexandra Feodorovna, in countless spiritual and political issues, Rasputin became an easy scapegoat for Russian nationalists, aristocrats and liberals., Jelena Karaorevi or Princess Helen of Serbia ( 4 November 1884 -- 16 October 1962 ) was the daughter of King Peter I of Yugoslavia and his wife Princess Zorka of Montenegro . She was the elder sister of George , Crown Prince of Serbia and King Alexander I of Yugoslavia . Helen was also a niece of Anastasia of Montenegro ( or `` Stana '' ) , wife of Grand Duke Nicholas Nikolaevich of Russia , and of Milica of Montenegro , wife of Grand Duke Peter Nicolaievich of Russia , the women who introduced Grigori Rasputin to Tsarina Alexandra . She was born Princess Jelena Karaorevi , became Princess Jelena of Serbia at the accession of her father and was known as Elena Petrovna , Jelena Petrovna , Hélène Petrovna or Ellen Petrovna after her marriage ., George, Crown Prince of Serbia (Serbian: "kraljevi ore Karaorevi"; 27 August 1887  17 October 1972) was the eldest son of King Peter I of the Serbs, Croats and Slovenes and Queen Ljubica (Zorka) of Montenegro. He was the older brother of King Alexander I of Yugoslavia., Saint Petersburg is Russia's second-largest city after Moscow, with five million inhabitants in 2012, and an important Russian port on the Baltic Sea. It is politically incorporated as a federal subject (a federal city). Situated on the Neva River, at the head of the Gulf of Finland on the Baltic Sea, it was founded by Tsar Peter the Great on May . In 1914, the name was changed from Saint Petersburg to Petrograd, in 1924 to Leningrad, and in 1991 back to Saint Petersburg. Between 17131728 and 17321918, Saint Petersburg was the imperial capital of Russia. In 1918, the central government bodies moved to Moscow., Alexander I ("Aleksandar I Karaorevi", ), also known as Alexander the Unifier ("Aleksandar Ujedinitelj", ,  9 October 1934) served as a prince regent of the Kingdom of Serbia from 1914 and later became King of Yugoslavia from 1921 to 1934 (prior to 1929 the Kingdom was known as the Kingdom of Serbs, Croats and Slovenes)., Subject: princess helen of serbia, Relation: ethnic_group, Options: (A) british (B) finland (C) polish (D) russia (E) serbs (F) slovenes
Output: serbs