The first bishop of Sigüenza, after it had been repeopled, was Bernardo, a native of Agen in France, who had been "capisol" (caput schola, Latin for school head(master)) of Toledo; he rebuilt the church and consecrated it on the Feast of St. Stephen, 1123, and placed in it a chapter of canons regular; he died Bishop-elect of Santiago.

On 14 March 1140, Alfonso VII granted the bishop the feudal lordship of Sigüenza, which his successors retained until the fourteenth century, making the diocese a minor prince-bishopric.

Pedro Gonzalez de Mendoza, the Crown Cardinal of Spain, held this diocese together with the archbishopric of Toledo, and enriched his relations by providing establishments for them at Sigüenza.

His successor, Cardinal Bernardino de Carvajal, was dispossessed as a schismatic by pope Julius II for his share in the Conciliabulum of Pisa.

Bishop of Sigüenza Fadrique de Portugal y Noroña became in the first third of the 16th Century, Archbishop of Zaragoza and Viceroy of Catalonia.