The Battle of Lobregal took place in March 1160 between the House of Lara and its allies and the forces of the House of Castro under Fernando Rodríguez de Castro. The battle was the high point of a series of struggles for power between the Lara and Castro families following the death of Sancho III of Castile in August 1158 and the accession of his young son, Alfonso VIII. In 1159 the Lara had seized the regency from Gutierre Fernández de Castro, Fernando's uncle.
Early in 1160 Fernando had been forced into exile at the court of Ferdinand II of León. According to Rodrigo Jiménez de Rada, writing in the early thirteenth century, he returned shortly with an army and inflicted a major defeat on his enemies, led by Nuño Pérez de Lara, brother of the young Alfonso's regent, Manrique, at Lobregal in the Tierra de Campos, near Villabrágima. The Anales toledanos primeros, under the year 1160, note an arrancada led by Nuño Pérez in the Tierra de Campos. An arrancada could refer to "as much to a violent incursion, in the style of a chevauchée, as to a military action that ends in serious defeat." Nuño's brothers Manrique and Álvaro may have been present at the battle also.
In the battle, Fernando's father-in-law, Osorio Martínez, died fighting alongside the Lara. Fernando also captured Nuño Pérez and Rodrigo Gutiérrez. Rodrigo's brother, Álvaro Gutiérrez, died on the field. The captive Lara leaders were released within a few days after swearing an oath to Fernando that they would return after burying Álvaro. Once free Rodrigo promptly placed Álvaro in a sarcophagus, but delayed his burial, believing this exempted him from returning to captivity. Nuño met Fernando at Dueñas with a following of six hundred knights. Under such circumstances Fernando did not dare attempt to take him captive again, and Nuño claimed he had upheld his end of the agreement. The Crónica General de 1344 records that Manrique, who in fact died at Huete four years later, had died on the field of Lobregal and that it was Nuño who received his freedom from captivity for the purpose of burying his brother. This confusion is shared by several other late sources.