Richard Zenith in Literary Hub:
When the ever elusive Fernando Pessoa died in Lisbon, in the fall of 1935, few people in Portugal realized what a great writer they had lost. None of them had any idea what the world was going to gain: one of the richest and strangest bodies of literature produced in the twentieth century. Although Pessoa lived to write and aspired, like poets from Ovid to Walt Whitman, to literary immortality, he kept his ambitions in the closet, along with the larger part of his literary universe. He had published only one book of his Portuguese poetry, Mensagem (Message), with forty-four poems, in 1934. It won a dubious prize from António Salazar’s autocratic regime, for poetic works denoting “a lofty sense of nationalist exaltation,” and dominated his literary résumé at the time of his death.
Some of Pessoa’s admirers—other poets, mostly—were baffled by the publication of Message, whose mystical vision of Portugal’s history and destiny seemed to rise up out of nowhere. In periodicals he had published other, very different kinds of poems, over half of which were signed by one of three alter egos, all of whom came into being in 1914, shortly before the outbreak of World War I.
More here.