After the success of 'A Fistful of Dollars', the film would become a classic and, in 1977, would be aired on TV. However, Clint Eastwood's murderous anti hero killed many people in the film, and Television executives feared that this may upset some viewers. So they filmed a prologue to give The Man With No Name a motivation for his crimes to appease 1977 TV audiences.
This was only aired once on TV until it was taken away because it changed the artistic vision of the film.