Kingdom of Aragon
The king of Navarre Sancho Garcés IV was assassinated by his own brother in 1076. The Navarrese, not wanting to be governed by the fratricide, elected Sancho Ramirez of Aragon -cousin of the deceased- as their king, who incorporated the crown of Pamplona to that of Aragon. The kingdom of Navarre was divided between León-Castile and Aragon; the latter received the main territories, including the capital of Navarre, and tripled its extension, although in exchange for admitting the theoretical supremacy of Castile-León. To celebrate the expansion, Sancho founded the city of Jaca, where he took up residence and to which he transferred the Mozarabic bishopric (of Hispano-Visigothic liturgical tradition under Muslim rule) of Huesca in 1077. As he controlled the highlands bordering the Ebro to the north, he was able to undertake various raids, mainly against the Zaragozan taifa, and try to expand into the plain, mainly along the valleys of Aragon, Sobrarbe and Ribagorza. To compensate for the lack of soldiers needed for territorial expansion, he tried to bring them from the south of France. Expansion, however, was slow and was carried out especially through the conquest of strategic points, such as Graus in 1083 and Ayerbe, around the same time. The advances towards the south were accelerated at the end of the century, both by the lack of support of Alfonso to the Zaragozans and by the march of the Cid to the Levant, who until then had fought with them. In 1089, the Aragonese seized Monzón, which hindered communications between Lérida and Huesca, and in 1091 they built the castle of El Castellar, between Zaragoza and Tudela. Sancho undertook the siege of the important city of Huesca -much larger than Jaca and Pamplona and probably than any peninsular city in Christian hands, except Barcelona and Toledo- in 1094, but died of an arrow shot. He was immediately succeeded by his son Pedro, already associated with power and who soon resumed the siege.