The phrase "a former era" is correct and usable in written English.
It can be used to refer to a past period in history or time that is distinct from the present.
Example: "The architectural style of the buildings reflects the values and aesthetics of a former era."
Alternatives: "a bygone age" or "a past period".
Many recent cases relate to a former era.
For starters, there are few grounds for believing, as Greenfield does, that a former era of mingled pride or scorn for science is giving way to fear.
Another terrific boxing writer of a former era, the Sun's Colin Hart, rightly noted that "every superlative to describe his [Ali's] skill and courage as a fighter was used up long ago".
They were moved around the country, from place to place, housed temporarily in palace ruins and other abandoned buildings from a former era – sometimes even in mental asylums.
When John McCain appears before the committee, he tries to invoke a former era by asking the committee chair: "Have you no shame, Sir?" But this line falls flat when he is immediately answered with: "No.
I'm assuming they're locked in a warehouse somewhere, gathering dust alongside Popples, talking Teddy Ruxpins and naiveté, all relics of a former era when children played naked and sported bowl cuts.
This park is built on the site of Villa Grimaldi, a former Pinochet era interrogation site and one of the most moving parts of any visit to this capital city.
Back in the former era, the motivation was clear enough.
Their criticisms may be valid from that former era, but not today.
We arrive at Rooms Hotel in Tbilisi, a former Soviet-era publishing and printing house.
Mystetskyi Arsenal, or Art Arsenal, is housed in a former tsarist-era weapons arsenal just opposite the Kiev Monastery of the Caves, one of the centers of Orthodoxy.
