The quote indicates a historical context, pinpointing the location and date related to an important literary work, specifically in Valladolid on December 20. It signifies the moment of recording or perhaps publishing a significant work of literature.
The reference is to "Don Quijote de La Mancha," authored by Miguel de Cervantes Saavedra, widely regarded as one of the first modern novels. This masterpiece reflects themes of chivalry, reality versus illusion, and critiques societal norms, marking a pivotal point in literary history.