Book of Knowledge of All Kingdoms

It is written in the form of imaginary autobiographical travelogue of a Castilian mendicant friar, as he travels through the entire world, known and fanciful, from the westernmost Atlantic islands, through Europe, Asia, Africa and the Arctic, identifying all the lands, kings, lords and their armorial devices as he passes them.

The full title is also cited as Libro del conosçimiento de todos los reynos y tierras y señoríos que son por el mundo, et de las señales et armas que han cada tierra y señorío por sy y de los reyes y señores que los proueen "Book of the Knowledge of all the Kingdoms, Lands and Lordships that are in the World, and the arms and devices of each land and lordship, or of the kings and lords who possess them" (Markham 1912).

Its choice of presenting itself in the form of an imaginary travelogue may have been whimsical, to tap into the fashionable travel literature of the era, popularized by Marco Polo and John Mandeville.

A manuscript copy of the Libro, once owned by the 16th-century historian Jerónimo Zurita y Castro, and subsequently held by the count of San Clemente in Zaragoza, was reported lost sometime around 1680.

However, immediately upon its appearance, contemporary scholars (not without a touch of mockery at the editor) noted the travelogue was largely fantastical and imaginary, and that there was no clear indication that the author was a friar, Franciscan or otherwise.