The era of contention among various principalities on the Iberian
Peninsula was an incubator of constitutional thought. As Christian
and Moorish nations fought, formed and reformed, rose and fell,
princes had to make some accommodations to the various players whose
support they needed. Some of this took the form of documents of a
constitutional character, many of which had an influence that
reached to other nations.
1241 Fuero Juzgo. Codex of Spanish laws enacted in Castile in 1241 by Fernando III. It is essentially a translation of the Liber Iudiciorum that was formulated in 654 by the Visigoths.
1265 Libro de las Leyes (Las Siete Partidas, "Seven-Part Code"). Castilian statutory code compiled under Alfonso X of Castile (1252–1284), followed for centuries in Latin America, up to the 19th century.
Fuero de León, Wikipedia (Spanish)
Medieval Iberia, edited by
E. Michael Gerli, Samuel G. Armistead
Extracto de las leyes del Fuero
viejo de Castillas, con el primitivo Fuero ...,
edited by Juan de la Reguera y Valdelomar
Colección de Cortes de los Reynos de
León y Castilla, Volume 1, by Real Academia de la Historia
Fuero Juzgo, Wikipedia. In 1348, the Ordenamiento de Alcalá granted it legal preeminence over the Siete Partidas. The Fuero Juzgo reigned until the creation of the Spanish Civil Code near the end of the nineteenth century. Presently, it retains some legal force with respect to certain auxiliary civil fueros in the Basque Country, Navarra, and Aragon.
Siete Partidas, Wikipedia. A "humanist encyclopedia," it addresses constitutional, philosophical, moral and theological topics.