 During this period the shire to which belonged change from one kingdom to another until finally passed to the kingdom of Castile after an award, in 1146.It appears that the population has its origin in the high-medieval repopulation, but it is not named till 1068 when appears in the endowment document of the episcopal see of Oca that the first king of Castile, Sancho II granted to its Bishop, linking it to Abbey "Foncea" or "Broncea".It is named in the fuero (charter) of Cerezo, which was granted by Alfonso VII of León and Castile, 10 January 1146, to the town of Cerezo de Río Tirón.