One of the undoubtedly greatest historical figures of medieval Galicia, the one who obtained the dignity of archbishopric for the Compostela see. Lord of Santiago, Diego Xelmírez greatly promoted the works of the cathedral (according to the Calixtino Codex, the last stone of the temple was placed under his mandate in 1122), and was in charge of beautifying an emerging city: a center of pilgrimage and commerce that needed new streets and buildings. It is believed that Xelmírez traveled to France and Rome, and it is known that he had very good relations with the greatest powers of Western Christendom at the time: the papacy (four were the popes who dealt with him) and the Abbey of Cluny. The Archbishop of Compostela became the highest ecclesiastical authority in the catholic part of the Iberian Peninsula for several years, at a time of great growth in the influx of pilgrims, promoted by the “thesis of the three sees” (Santiago, Rome and Jerusalem), which it designated these three cities as the most important centers of devotion in all of Christendom.
The life and work of Xelmírez are collected in his commissioned Historia Compostellana (in Latin), a key piece for understanding the complex medieval history of the western Hispania. This series of books narrates what happened in Santiago since the discovery of the apostolic tomb to the death of Xelmírez himself, focusing with almost biographical ways in the time of this first archbishop.
Diego Xelmírez was born around 1065 into a noble family that ruled some of the coastal lands of the Compostela bishopric, in the Catoira area. His education was already from the first moment oriented to religious life; he completed his education at the Santiago cathedral school with a stay at the Leonese court of the then reigning Alfonso VI.
He was elected while still very young councilor and secretary of the new counts of Galicia: Raimundo de Borgoña and Urraca de León. Alfonso VI had created this position with the intention of pacifying the kingdom of Galicia, which in previous decades had rebelled on several occasions against the central power (even achieving independence under García I). In 1093, during the bishopric Dalmacio, Xelmírez was appointed administrator of the diocese, a position from which he devoted himself mainly to advancing the works of the cathedral. A few years later, in 1095, the papal bull arrived that authorized the definitive transfer of the episcopal see from Iria Flavia to Santiago, leaving it only subject to Roman authority (a great step considering that previously, the see of Iria depended on the recently restored see of Braga).
After Dalmacio’s death, with the support of the counts, the papacy, and the Abbey of Cluny, Diego Xelmírez became the new bishop of Santiago. Since then, he was accumulating influence and merits always with the aim of obtaining the archbishopric, which would not come until 1120 from the hands of Pope Calixto II (brother of the late Count Raymond). These were the most important moments, achievements and events of those first 20 years of Xelmírez’s government: obtaining the power to mint currency (a dignity that he only shared with kings; his currency was made in common use throughout Galicia), the Pío Latrocinio (a very interesting historical event that consisted of the theft by Xelmírez of important relics from Braga and their subsequent transfer to Santiago with the intention of increasing the prestige of its headquarters against the competition), some popular revolts (the city, a commercial center, it had a thriving bourgeoisie that several times rose up against its lord), the construction of the first navy of the Christian peninsula (a fleet that was built around 1115 in the Arousa estuary as an effective defense against Viking and Saracen attacks), and finally, several treaties and wars with Urraca and Alfonso el Batallador (related to the defense of the autonomy of the kingdom of Galicia and the desire to increase it).
In 1120, Xelmírez and Compostela became archbishop and archbishopric, with the transfer of the title from the Muslim Mérida (to avoid problems with the sees of Braga and Toledo). In addition, the Lord of Santiago was also appointed papal legate, being then the highest ecclesiastical authority in Hispania, with the power to convene councils. Finally, and thanks to Urraca (with whom he had a complicated relationship, from friends to enemies and back again), Xelmírez also performed the functions of Count of Galicia.
Together with Pedro Froilaz, count of Traba (a powerful Galician nobleman with very good relations on the other side of the Miño), the archbishop defended and took charge of the upbringing of the future Alfonso VII, first crowned king in Santiago, and in 1126 in León. The truth is that once grown up, the new king did not serve the interests of Xelmírez and did not favor the power of Compostela; quite the contrary, since Alfonso VII, due to his numerous military campaigns, constantly asked the archbishopric for money.
Although in 1124 with the death of Calixto II he ceased to be a pontifical legate, Xelmírez continued to be one of the greatest religious and political authorities in Galicia and León until his death in office in 1140. Of fundamental importance for the economic, cultural and political projection of medieval Santiago, Diego Xelmírez is studied as an astute leader, the architect of complicated diplomatic maneuvers, which did not always go well but which led to (after many attempts) Compostela being archbishopric and Xelmírez, its first archbishop.