Treaty of Sahagún
The Treaty of Sahagún ended a state of war between the Castile and León, establishing pacem et ueram amiciciam (peace and true friendship) between their respective monarchs, Sancho III and Ferdinand II, who called themselves boni fratres et boni amici (good brothers and good friends). It was signed at the monastery of Sahagún on 23 May 1158.On the death of Alfonso VII (21 August 1157) his realms were partitioned between his two sons: Castile, with Toledo to the eldest, and León, with Galicia, to the younger one. According to Rodrigo Jiménez de Rada, this division was instigated by the factitious Manrique Pérez de Lara of Castile and Fernando Pérez de Traba of León, who, the historian says, "aimed to sow the seed of discord thereby." According to Rodrigo, Ferdinand II, in response to calumnious accusations at court, confiscated the fiefs of some of his leading magnates, who then went into exile at the court of Sancho III, seeking redress. The Castilian king marched on army on León, but Ferdinand arranged to meet him at Sahagún and a peace was negotiated. The documentary sources do not provide a clear chronology of the exile of any magnates, although it is known to have occurred. Later sources connected these events with the (probably legendary) Mutiny of the Trout.The Treaty of Sahagún put an end to the quarrel. It stipulated that Sancho should return the seized lands to his brother, but also that they should be held in fidelitate (in fealty) from Ferdinand by three counts: Ponce Giraldo de Cabrera,.
1158 treaty between Castile and León
peace treaty