Today is the claimed or maybe presumed or only hoped-for birthday of Miguel de Cervantes (1547). He did a lot of different things, but the one we remember him for is Don Quixote (1605/1615), the parody of knightly romances so popular in Spain during the sixteenth century. Not only is it the first major instance of a novel in the modern sense, it is highly postmodern not only in its self-referentiality (mainly in part 2) and its cunning intertextuality, from his habit of reusing, quoting, and sometimes savaging other works. In part 2, Quixote and Sancho Panza find they have become famous as a result of a book about their earlier adventures. Pretty subtle for an early novel, but then, see also, Shakespeare and plays-within-plays.
While the novel is important the world over, its centrality in the Spanish-speaking world cannot be overstated. Carlos Fuentes said that he reread it every year; he also raised the possibility that Cervantes and Shakespeare were the same person, which is one reason I like Fuentes so much. He may have meant that they were embodiments of the same spirit or genius, but then again, he may not have. They died on the same date, you know, so maybe he was on to something.