These are the preliminary essays in the stuff of Spanish prose. Its permanent form was received at the hands of ALFONSO THE LEARNED (1226-84), who followed his father, St. Ferdinand, to the Castilian throne in 1252. Unlucky in his life, balked of his ambition to wear the title of Emperor, at war with Popes, his own brothers, his children, and his people, Alfonso has been hardly entreated after death. Mariana, the greatest of Spanish historians, condenses the vulgar verdict in a Tacitean phrase: _Dum cœlum considerat terra amissit_. A mountain of libellous myth has overlaid Alfonso's fame. Of all the anecdotes concerning him, the best known is that which reports him as saying, "Had God consulted me at the creation of the world, He would have made it differently." This deliberate invention is due to Pedro IV. (the Ceremonious); and if Pedro foresaw the result, he must have been a scoundrel of genius. Fortunately, nothing can rob Alfonso of his right to be considered, not only as the father of Castilian verse, but as the centre of all Spanish intellectual life. Political disaster never caused his intellectual activity to slacken. Like Bacon, he took all knowledge for his province, and in every department he shone pre-eminent. Astronomy, music, philosophy, canon and civil law, history, poetry, the study of languages: he forced his people upon these untrodden roads. To catalogue the series of his scientific enterprises, and to set down the names of his Jewish and Arab collaborators, would give ample work to a bibliographer. Both the _Tablas Alfonsis_ and the colossal _Libros del Saber de Astronomía_ (Books on the Science of Astronomy) are packed with minute corrections of Ptolemy, in whose system the learned King seems to have suspected an error; but their present interest lies in the historic fact, that with their compilation Castilian makes its first great stride in the direction of exactitude and clearness.