Boris Nemtsov (Борис Ефимович Немцов) was born on Oct. 9, 1959, in Sochi.

Education: Gorky State University, radiophysics (1981). Ph.D. physics and mathematics (1985).

1981-1990: Researcher at the Gorky Radiophysics Research Institute

1990: Elected to the Soviet Congress of People's Deputies. Member of the Supreme Soviet's Legislative Committee.

1991: Appointed governor of the Nizhny Novgorod region (re-elected in 1995 with 58.9 percent of the vote). Nemtsov had strongly supported President Yeltsin throughout the late 1990s.

1993: Elected to the Federation Council. During the campaign, he was backed by Russia's Choice and Yabloko, the two main liberal parties at the time.

1997: Appointed first deputy prime minister. He was charged with reforming the energy sector.

1998: Resigns from deputy prime minister post twice in the wake of the 1998 financial crisis (Nemtsov had been a member of Anatoly Chubais' economic reform team)

1999: Co-founded the liberal-democratic Union of Right Forces. Elected to the State Duma, becoming its deputy speaker.

2000-2004: Party leader of the Union of Right Forces (replacing Sergei Kiriyenko). He resigned after the party failed to win any seats in Duma elections in 2003.

2005-2006: Economic adviser to Ukrainian President Viktor Yushchenko

2007: Withdrew his candidacy for the presidency, saying he wanted to avoid splitting the liberal vote with another candidate, Mikhail Kasyanov

2008: Co-founded the opposition movement Solidarity with Garry Kasparov to unite the various opposition groups

2008: Came second in the election for mayor of Sochi, scoring only 13 percent of the vote compared with 77 percent for the Kremlin-backed candidate, Anatoly Pakhomov

2011: Spent 15 days in jail after leading a public demonstration against restrictions on the freedom of assembly

Nemtsov is married and has four children.