Ranković was a member of the Politburo from 1940. After he was captured and tortured by the Gestapo in 1941, he was rescued by a daring Communist raid. He served on the Supreme Staff throughout the war. He was named a "People's Hero" (Hero of the People's War of Liberation) for his services during World War II.
After the war, he was minister of the interior and head of the military intelligence ("OZNA") and political police ("UDBA"). He fell from power in 1966, ostensibly for abusing his authority in bugging the sleeping quarters of Josip Broz Tito in Belgrade. He was expelled from the Communist Party of Yugoslavia in the same year.
His fall from power marked the beginning of the end of the centralized command of the League of Communists of Yugoslavia over the country and the social and political separatist and autonomist movements that would culminate in the Croatian Spring and the new de-centralized Yugoslavia that emerged from the 1971 constitutional reforms and later in the all-new 1974 Constitution.
After that, he lived in Dubrovnik until the end of his life. His funeral in Belgrade in 1983 was the occasion for a huge outpouring of grief, as Ranković had come to symbolize Serbian strength.