Golden age

A golden age was an era or epoch regarded as superlative for some reason.

Operation Golden Age was a plan to return Earth to a pre-industrial age (TV: Invasion of the Dinosaurs)

Britain's Golden Age was the Ninth Doctor's name for an era, later aborted by the Tenth Doctor, in which Harriet Jones had a long and successful term as prime minister, which he discovered was not as pleasant as it sounded due to her unethical involvement with Torchwood One. (TV: World War Three, The Christmas Invasion) Pete Tyler of a parallel universe also referred to the Jones of his universe as reigning under this age. (TV: Doomsday)

Elton Pope described his time with the group which he named LINDA as a golden age, which ended when Victor Kennedy joined the group. (TV: Love & Monsters)