golden age 
noun
1An idyllic, often imaginary past time of peace, prosperity, and happiness: he hankered after a lost golden age...
- Critics could rightly charge that the report had waxed nostalgic about an imaginary golden age.
- But the evidence proves the Mesolithic was hardly a golden age of peace and universal goodwill between people.
- Elsewhere, the empire is generally considered to have been enjoying a golden age of tranquillity and prosperity.
1.1The period when a specified art or activity is at its peak: the golden age of cinema...
- It celebrates not only Christmas but the artistic and commercial peak of the golden age of popular song writing.
- She is like a screen siren from the golden age of cinema - composed, elegant and glamorous.
- Research has shown that knowledge of this art had its golden age at some remote period in the past.
Origin
Mid 16th century: the Greek and Roman poets' name for the first period of history, when the human race lived in an ideal state.