fadedsignals:

As CBS enjoyed huge success with its prime-time soap opera “Dallas” in the early 1980s, ABC responded with its own prime-time soap.  

The Aaron Spelling-produced series “Dynasty” debuted in 1981, featuring the drama surrounding the Carringtons, a wealthy Denver family. John Forsythe and Linda Evans starred in the show and Joan Collins joined the cast in the second season.

After weak ratings in the first season, the producers revamped the series and it became the top-rated show by the 1984 season. Ratings declined steadily thereafter, and the show was canceled at the end of its ninth season in 1989. As the prime-time soap genre died, the ratings for “Dallas” also collapsed. It was canceled in 1991.  

Source: Wikipedia (”Dynasty”)