Fragmentary, hidden diary, text of anguished introspection, attempt to explore the phenomenon of existence, tracing the boundaries between being and non-being, but above all an endless self-narration, is the "Book of Disquiet" where, behind the confessions of the transparent assistant accountant Bernardo Soares, we discern one of the dominant figures of 20th-century world literature, the Portuguese poet Fernando Pessoa. The work he left almost entirely unpublished, dying in 1935, is vast and multifaceted: a large part of it is signed by the "heteronyms," creations of the poet's imagination that possess an autonomous literary style and work, as well as an autonomous fictitious biography. As it begins to become known through its gradual publication, it reveals the man who sought to build an entire literature on his own. The "Book of Disquiet" was first published in Portugal in 1982 and has been recognized through its multiple translations as one of the key works that mark the century.