When did heteronymy begin? Alberto Caeiro, Álvaro de Campos and Ricardo Reis — all of whom emerged in 1914 — are usually regarded as the only heteronyms truly deserving of this designation, but they’re part of what we may call the “heteronymous system”, which goes back to the writer’s youth. The famous trio qualitatively stands apart from Pessoa’s other fictitious authors, but their defining characteristics — their “dramatic” or feigned way of expressing themselves in poetry and prose, their attitudes and opinions that often diverge from those of their creator, the interactions between them and Pessoa himself, their occasional “presence” in real life (Campos), and the fact they have their own biographies and signatures — can all be found in the pseudo-authors who preceded them in the said system. This essay includes the transcription of an astonishing, previously unpublished letter in English, supposedly written by the comic heteronym Gaudêncio Nabos and sent to Pessoa from London on 26/II/1906.