Adolf Abramovich Joffe was born in Simferopol, Crimea, Russian Empire in a wealthy Karaite family. He became a social democrat in 1900 while still in high school, formally joining the Russian Social Democratic Labor Party in 1903. In 1904 Joffe was sent to Baku, which he had to flee to avoid arrest. He was then sent to Moscow, but had to flee again, this time abroad. After the events of Bloody Sunday on January 9, 1905, Joffe returned to Russia and took an active part in the Russian Revolution of 1905. In early 1906 he was forced to emigrate and lived in Berlin until his expulsion from Germany in May 1906.