Pessoa’s legacy consisted of a large trunk full of poetry, prose, plays, philosophy, criticism, translation, linguistic theory, political writings, horoscopes, and assorted other texts, variously typed, handwritten or illegibly scrawled in Portuguese, English and French. He wrote in notebooks, on loose sheets, on the backs of letters, advertisements and handbills, on stationery from the firms he worked for and from the cafes he frequented, on envelopes, on paper scraps, and in the margins of his own earlier texts. To compound the confusion, he wrote under dozens of names, a practice—or compulsion—that began in his childhood. He called his most important personas ‘heteronyms’, endowing them with their own biographies, physiques, personalities, political views, religious attitudes and literary pursuits. Some of Pessoa’s most memorable work in Portuguese was attributed to the three main poetic heteronyms—Alberto Caeiro, Ricardo Reis and Alvaro de Campos—and to the ‘semi-heteronym’ called Bernardo Soares, while his vast output of English poetry and prose was in large part credited to heteronyms Alexander Search and Charles Robert Anon, and his writing in French to the lonely Jean Seul. The many other alter egos included translators, short-story writers, an English literary critic, an astrologer, a philosopher and an unhappy nobleman who committed suicide. There was even a female persona: the hunchbacked and helplessly lovesick Maria Jose. At the turn of the century, sixty-five years after Pessoa’s death, his vast written world had still not been completely charted by researchers, and a significant part of his writings was still waiting to be published.

--Introduction to Book of Disquiet, Richard Zenith (2001)