San Esteban de Gormaz
In 1060, according to the "Historia silense", Ferdinand invaded the "taifa" of Zaragoza through the upland valley of the eastern Duero in the highlands around Soria. He captured the fortresses of San Esteban de Gormaz, Berlanga and Vadorrey, and afterwards proceeded through Santiuste, Huermeces and Santamara as far as the Roman road that lay between Toledo and Zaragoza. The success of the campaign was made possible by the preoccupation of the Zaragozan emir, Ahmad al-Muqtadir, with attacking the neighboring "taifa" of Tortosa and defending his northeastern frontier from Ramiro I of Aragon and Raymond Berengar I of Barcelona. The emir, up until then paying tribute to Sancho IV of Navarre, submitted to Ferdinand and agreed to pay "parias". Although probably originally meant to be temporary, Ferdinand managed to enforce the tribute until his death.