Alonso Díaz de Montalvo was a Spanish

Spain

Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

 jurist.

After studying law at Lleida

Lleida

Lleida is a city in the west of Catalonia, Spain. It is the capital city of the province of Lleida, as well as the largest city in the province and it had 137,387 inhabitants , including the contiguous municipalities of Raimat and Sucs. The metro area has about 250,000 inhabitants...

 and Salamanca

Salamanca

Salamanca is a city in western Spain, in the community of Castile and León. Because it is known for its beautiful buildings and urban environment, the Old City was declared a UNESCO World Heritage Site in 1988. It is the most important university city in Spain and is known for its contributions to...

, he served in high judicial and administrative offices under the Catholic Monarchs

Catholic Monarchs

The Catholic Monarchs is the collective title used in history for Queen Isabella I of Castile and King Ferdinand II of Aragon. They were both from the House of Trastámara and were second cousins, being both descended from John I of Castile; they were given a papal dispensation to deal with...

. In 1480, he was commissioned to draft the Libro de Leyes, also known as Ordeniamento de Montalvo, a unifying codification of the law of Leon

Kingdom of León

The Kingdom of León was an independent kingdom situated in the northwest region of the Iberian Peninsula. It was founded in AD 910 when the Christian princes of Asturias along the northern coast of the peninsula shifted their capital from Oviedo to the city of León...

 and Castile

Kingdom of Castile

Kingdom of Castile was one of the medieval kingdoms of the Iberian Peninsula. It emerged as a political autonomous entity in the 9th century. It was called County of Castile and was held in vassalage from the Kingdom of León. Its name comes from the host of castles constructed in the region...

that would remain in effect, in large parts, up until the 19th century.