Widely considered one of the most significant and influential figures of the 20th century, Lenin was the posthumous subject of a pervasive personality cult within the Soviet Union until its dissolution in 1991. He became an ideological figurehead behind Marxism–Leninism and a prominent influence over the international communist movement. A controversial and highly divisive historical figure, Lenin is viewed by his supporters as a champion of socialism, communism, anti-imperialism and the working class, while his critics accuse him of establishing a totalitarian dictatorship that oversaw mass killings and political repression of dissidents.