Short answers, pulled from the story.
The Azerbaijan People's Government was an unrecognized secessionist state in northern Iran that existed from November 1945 to December 1946. It was a Soviet-backed autonomous republic headquartered in Tabriz, led by Ja'far Pishevari and the Azerbaijani Democratic Party. It was created by direct order of Joseph Stalin as part of Soviet efforts to secure an oil concession in Iranian Azerbaijan.
Stalin backed the Azerbaijan People's Government primarily to pressure Iran into granting an oil concession in Iranian Azerbaijan. A Soviet-Iranian oil agreement concluded in March 1946 gave the USSR 51 percent ownership and effective control of northern oil resources, though the Iranian Majlis ultimately refused to ratify it, voting 102 to 2 against on the 22nd of October 1947.
Ja'far Pishevari, a veteran communist and long-time leader of the revolutionary movement in Gilan, headed the Azerbaijani Democratic Party and the government. Lavrenti Beria held nominal Soviet oversight but delegated day-to-day control to Mir Jafar Baghirov, First Secretary of the Communist Party of Azerbaijan in Baku.
Under pressure from the Western powers, the Soviet Union withdrew its military support, and the Iranian army backed by the United States and Britain reentered Tabriz on the 11th of December 1946, collapsing the government. Pishevari and his cabinet fled to the Soviet Union. Approximately 500 supporters of the Ferqeh were killed in Tabriz before and after the army's return.
Ja'far Pishevari fled to the Soviet Union when the Iranian army reentered Tabriz in December 1946. He died in a car accident in Baku in 1947.
Its establishment and demise are considered an early event of the Cold War, known as the Iran crisis. The United States supported Iran's complaints at the UN Security Council through Resolution 3 and Resolution 5, and U.S. ambassador George V. Allen publicly condemned foreign coercion over Iranian resources on the 11th of September 1947. The episode represented one of the first direct confrontations between Soviet expansion and Western resistance in the postwar era.