In August 1492 Spanish scholar Antonio de Lebrija (also known as Elio Antonio de Lebrija, Antonius Nebrissensis, Aelius Antonius Nebrissensis, and Antonio of Lebrix; given name: Antonio Martinez de Calá) published Gramática de la lengua castellana, also known as the Grammatica Nebrissensis, and, in 15th century Spanish, Grammatica dela Lingua Castellianna. This work of 68 pages was published in Salamanca by an unidentified printer.
This was the first work dedicated to the Castillian or Spanish language, its orthography, prosody and syllables, etymology, diction, and syntax. It was also the first printed grammar of a spoken language, rather than Latin, the grammar of which was based on the written, rather than spoken language.
In July 2011 a digital facsimile of the first edition was available from the Universidad Complutense de Madrid at this link.
Illich, In the Vineyard of the Text (1993) 73.