The Fuero Real was undoubtedly his work, and he began the code called the Siete Partidas, which, however, was only promulgated by his great-grandson.
The "fuero general" does not profess to supersede the consuetudines antiquorum jurium or Chindaswint's codification of these in the Lex Visigothorum; the "fuero municipal" is really for the most part but a resuscitation of usages formerly established, a recognition and definition of liberties and privileges that had long before been conceded or taken for granted.
In the fuero of Cardena, for example, granted by Ferdinand I.
Latterly the word fuero came to be used in Castile in a wider sense than before, as meaning a general code of laws; thus about the time of Saint Ferdinand the old Lex Visigothorum, then translated for the first time into the vernacular, was called the Fuero Juzgo, a name which was soon retranslated into the barbarous Latin of the period as Forum Judicum; 4 and among the compilations of Alphonso the Learned in like manner were an Espejo de Fueros and also the Fuero de las leyes, better known perhaps as the Fuero Real.
The famous code known as the Ordenamiento Real de Alcald, or Fuero Viejo de Castilla, dates from a still later period.