1. the period of greatest success, popularity, or vigor

Examples

• The 1960s were the heyday of rock and roll music.
• During its heyday, the company employed over 10,000 workers.
• Many consider the Renaissance to be the heyday of European art.
• The old theater saw its heyday in the 1940s and 1950s.
• In her heyday as a tennis player, she won three Grand Slam titles.
• The heyday of the railroad industry lasted from 1860 to 1920.