A Ukrainian court's sentencing of former prime minister Yulia Tymoshenko to seven years in prison for abuse of office on Tuesday is the latest setback to the volatile career of the country's most prominent female politician.

Born in 1960 in the eastern city of Dnipropetrovsk, Ms. Tymoshenko entered the public spotlight in the mid-1990s as the head of an energy company that imported Russian natural gas for Ukraine's industrial sector.

Like many tycoons in Ukraine, Ms. Tymoshenko took an interest in politics and entered parliament in 1996. She was appointed deputy prime minister in charge of the energy sector in 1999 under the presidency of Leonid Kuchma, but fell out with the president and was held in prison for a month on corruption charges.

Ms. Tymoshenko rose to global prominence in 2004 when she helped to lead the Orange Revolution protests against a rigged presidential election that went in favor of pro-Russian candidate Viktor Yanukovych. She backed losing candidate Viktor Yushchenko's campaign to overturn the results and became his prime minister when he took office as president in 2005.

The two allies fell out, and Mr. Yushchenko fired Ms. Tymoshenko after less than eight months. They later reconciled, leading to her reappointment as prime minister in 2007. In her second term, she patched up her differences with Moscow, meeting her Russian counterpart, Vladimir Putin, in 2009 to sign the gas deal that later landed her in prison.

Ms. Tymoshenko ran for the post of president in a 2010 election but narrowly lost to Mr. Yanukovych before lawmakers ousted her as prime minister. She has since served as leader of the opposition.