The history of the Sirians is not significantly different from the history of the Pleiadeans or Nordics, but they have been given bad press. They are blamed with seeding the Earth with their rejects, malevolent desires to possess the Earth, and at times it seems with any floating blame that has nowhere else to go. Who did that? It was probably the Sirians, they're a bad bunch. How did all this misperception get started? In the same manner that misperceptions have developed about ourselves, the Service-to-Other Zetas, and the hominoids from Orion, and the reptilians, and even aliens in general.
Almost without exception every alien life form currently visiting Earth has both ambassadors in the Service-to-Self and Service-to-Other orientation, as except for rare instances where 3rd Density visitors are escorted to Earth, all visitors are in 4th Density or higher and have chosen their orientation. Where ambassadors from the Service-to-Other orientation are self effacing and honest and work behind the scenes, the ambassadors from the Service-to-Self are given to ceremony and false promises and like to make an impression. Thus your governments met these ambassadors first, and dealt with their deception and takeover agendas first, before coming to the realization that there are two distinct orientations afoot and they had rolled out the red carpet for the wrong one.
Rumors usually started flying about the time the honeymoon was ending, and since these rumors suited those Earthlings who wished humans to keep all aliens at arms length, they have never stopped flying. Rather, they have been fed, sparks fanned into flames by false stories, by those in the employ of certain establishment elites. The vast bulk of all information on aliens that is floated as truth, leaked by someone with credentials, verified by this or that person who should know, or found on old paper or in the files of someone now deceased - is concocted information. And where the vast majority of aliens contacting humans are in the Service-to-Other orientation, these false stories almost invariably describe aliens with the characteristics of the Service-to-Self.