The story
Originally Vulgar Era. The English phrase common Era appears at least as early as 1708, and by 1715 is used synonymously with Christian Era and Vulgar Era.
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: The secular equivalent of anno Domini and the Christian Era, the internationally recognized method of numbering years on the Gregorian calendar. Full definition →
Originally Vulgar Era. The English phrase common Era appears at least as early as 1708, and by 1715 is used synonymously with Christian Era and Vulgar Era.
Etymology from Wiktionary, CC BY-SA 4.0.