The Russian financial crisis, also known as the Ruble Crisis, began on August 17, 1998, when the Russian government defaulted on its domestic debt and devalued the ruble. This triggered a global financial market reaction and significant economic turmoil in Russia. The other dates are incorrect - June 1999 was after the crisis, July 1990 precedes the post-Soviet era, and February 2008 is unrelated to this specific crisis.