by Lisbon. This allotment appears in hindsight severely limiting to León, but which would not have seemed that way at the time. The most important part of the treaty declared that if either king should die, his kingdom was to pass to the other. Ferdinand named Ramiro Fróilaz, Pedro Alfonso, Ponce de Minerva and Abril as guarantors of his faith. There forty other lay and clerical confirmants, including Sancha Raimúndez, styled regina (queen), the brothers' aunt, and four bishops (of, in order of precedence, Palencia, Zamora, Astorga, and León). Thirty-three lay noblemen also subscribed, in one of two lists depending on their kingdom. Notably, while Ponce de Minerva is named among those who ex parte regis Fernandi iuraument (of the part of King Ferdinand swore the oath), Ponce de Cabrera is listed among the Castilians, probably an exile from León. Sancho III died on 31 August and Ferdinand promptly made a claim on Castile and occupied some territories, while the Castilian aristocracy descended into a civil war for control of Sancho's heir, Alfonso VIII. Notes References Simon Barton. 1992. "Two Catalan magnates in the courts of the kings of León-Castile: The careers of Ponce de Cabrera and Ponce de Minerva re-examined." Journal of Medieval History. 18:3, 233–66. Simon Barton. 1997. The Aristocracy in Twelfth-century León and Castile. Cambridge: Cambridge University Press. Julio González. 1982. "Fijación de la frontera castellano-leonesa en el siglo XII." En la España medieval, 2, 411–24. 12th-century treaties Peace treaties of Spain Treaties of the Kingdom of León Treaties of the Kingdom of Castile 1158 in Europe 1158 12th century in Castile 12th century in the Kingdom of León