Obviously when we think of secret identities we naturally think of super heroes, but the idea of a secret identity pre-dates the super hero as we know them today.
What I’m trying to figure out is, who was the first person in literature with a secret identity? The earliest I can think of was the Scarlet Pimpernel (1905). Does anyone have an earlier example?
I’m excluding people who adopted simple disguises (e.g. Sherlock Holmes counts when sleuthing about). That’s not something we would call a secret identity in the classic sense.
I don’t think Robin Hood counts either. Even though he adopted a new name and distinctive costume and nobody knew who he was, which are hallmarks of a secret identity, he didn’t lead a dual life as Robin Hood by night, Earl of Loxley (or whatever, depending on the version) by day, which I would say is also a key requirement. Robin Hood wasn’t a secret identity, it was just a new identity.
So I’m stumped for examples earlier than the Scarlet Pimpernel, but I can’t believe there aren’t any.