The dissolution of the Soviet Union was formally enacted on December 26, 1991, as a result of the declaration no. 142-Н of the Soviet of the Republics of the Supreme Soviet of the Soviet Union. The declaration acknowledged the independence of the former Soviet republics and created the Commonwealth of Independent States (CIS), although five of the signatories ratified it much later or not at all. On the previous day, Soviet President Mikhail Gorbachev, the eighth and last leader of the Soviet Union, resigned, declared his office extinct, and handed over its powers – including control of the Soviet nuclear missile launching codes – to Russian President Boris Yeltsin. That evening at 7:32 p.m., the Soviet flag was lowered from the Kremlin for the last time and replaced with the pre-revolutionary Russian flag. 

Mikhail Gorbachev was elected General Secretary by the Politburo on March 11, 1985, three hours after predecessor Konstantin Chernenko's death at age 73. Gorbachev, aged 54, was the youngest member of the Politburo. His initial goal as general secretary was to revive the Soviet economy, and he realized that doing so would require reforming underlying political and social structures. The reforms began with personnel changes of senior Brezhnev-era officials who would impede political and economic change. On April 23, 1985, Gorbachev brought two protégés, Yegor Ligachev and Nikolai Ryzhkov, into the Politburo as full members. He kept the "power" ministries happy by promoting KGB Head Viktor Chebrikov from candidate to full member and appointing Minister of Defence Marshal Sergei Sokolov as a Politburo candidate.
What was his original aims as secretary?
His initial goal as general secretary was to revive the Soviet economy, 