Russian privatization describes the series of reforms that resulted in the large-scale privatization of state-owned assets immediately after the collapse of the Soviet Union, most importantly in the industrial, energy, and financial sectors. Most privatization took place in Russia in the early and mid-1990s, during the presidency of Boris Yeltsin, who assumed the presidency immediately after the dissolution of the Soviet Union. Although Mikhail Gorbachev relaxed restrictions on private ownership in the mid to late 1980s, private ownership of enterprises and property had essentially been illegal throughout the Soviet era. Privatization enabled Russia to shift from the deteriorating Soviet planned economy towards a market economy, but, as a result, a good deal of the national wealth fell into the hands of a relatively small group of so-called business oligarchs (tycoons), and the wealth gap increased dramatically. It was described as "Catastroika" and as one of the "most cataclysmic peacetime economic collapse of an industrial country in history". A few "strategic" assets, including much of the Russian military industry, were not privatized during the 1990s. The mass privatization of the 1990s remains a highly contentious issue in Russian society today, with many Russians calling for significant revisions or even a general reversal of the reforms. Indeed, many Russians view the privatization quite critically and hold strongly negative views towards its chief architects, notably Anatoly Chubais and Yegor Gaidar.