The history of dictatorships are almost exclusively left wing.
They are exclusively left-wing, when examined even going back through history.
I do not believe that is quite accurate.
The history of totalitarian dictatorships are almost exclusively left wing.
Examples are: Soviet Union, NAZI Germany, Italian Fascists, Chinese Communists, Pol Poi, Cuba, Venezuela, North Korea.
Right wing dictatorships tend not to be totalitarian, because they are attempting to conserve culture and way of life. Examples:
Franco, Pinochet, Stroessner in Paraguay, Somoza in Nicaragua, Batista in Cuba, the military junta in Argentina and Bolivia and Honduras and El Salvador and just about every other Central and South American country.
Totalitarianism is not just a leftist solution. Right wingers have resorted to it many times as well.