Monarchy on the move
Ferdinand III of Castile and León: Historical study

In the Middle Ages, as was the case until just a few centuries ago, the monarchs of various European kingdoms traveled with their courts throughout their territories to assert their authority and carry out a variety of administrative, fiscal, legislative, and judicial functions. Since kings issued documents during these constant travels, it is possible to determine their routes and analyze certain spatial patterns that allow for a better understanding of the nature of the monarchy, its relationship with the territory and its inhabitants, as well as the political and cultural circumstances that explain this itinerancy.

What motivates royal travel, what are its characteristics, and what patterns can be observed in these movements? Which places are frequented by the court, and what explains the absence of a royal presence in other regions? What seasonal, climatic, practical, or functional considerations determine the monarchy’s itinerancy? What do these patterns of movement reveal about core aspects of the monarchy and political history? At what pace does the court travel, and what factors affected the speed of these journeys?

These are all questions that historians have addressed using the methodologies typical of scientific research, although, in reality, not as much has been published as the historical significance of this subject warrants. In this regard, the project Monarquía en Movimiento provides a georeferenced foundation for the analysis of the phenomenon through computational processing that verifies or refutes the intuition of human work and has the potential to open up new lines and perspectives of research.

A royal charter issued by King Ferdinand (FERRANDUS) in Soria in 1218 (detail).

Ferdinand III reigned over Castile from July 2, 1217, and also over the Kingdom of León from 1230 until his death on May 30, 1252, although the first official document of his reign was issued in Burgos on September 6, 1217, and the last in Seville on May 18, 1252. This is the time frame for the maps that visualize the king’s movements in this project, as it corresponds to the travels of a reigning monarch and not from his birth in June 1201 in Peleas de Arriba, near the Monastery of Nuestra Señora de Valparaíso (Zamora).

Infante Ferdinand’s accession to the Castilian throne and later to the Leonese throne was a rather eventful affair and was not without major intrigues and disputes. Following the death of Alfonso VIII of Castile in 1214, he was succeeded by his son Henry, a young man of only 13 years of age who died accidentally three years later, bringing to a premature end a reign administered by his older sister, Berenguela. She was entitled to the succession rights, becoming the second woman in Spanish history, after Queen Urraca (1109–1126), to fully exercise the monarchy in her own right. However, fearing claims from León to the throne of Castile, she decided to abdicate and have her son, Ferdinand, proclaimed king on June 14, 1217, in Autillo de Campos (Palencia). Berenguela abdicated in favor of the firstborn son she had borne to Alfonso IX, King of León, a marriage that had been annulled by Pope Innocent III in 1204 due to the consanguinity of the spouses.

The coronation and official recognition of Ferdinand III as King of Castile took place in Valladolid on July 2, 1217. He was the unlikely heir of his grandfather, Alfonso VIII, who was burdened by his illegitimate status due to the annulment of his parents’ marriage and who ascended to the throne following the unexpected death of his uncles and thanks to his mother’s political acumen and foresight.

“Doña Berenguela Crowning Her Son Don Fernando” (1866) by Mariano de la Roca y Delgado.

The same would happen with the succession to the throne of León following the death of Alfonso IX in 1230. Pope Honorius III had confirmed Ferdinand III as heir, but his half-sisters, the Infantas Sancha and Dulce—daughters of Alfonso IX and his first wife, Teresa of Portugal—were also claimants to the throne. The nobles of the kingdom were divided on the matter, but Ferdinand and Berenguela acted with intelligence and speed to reach the city of Toro and secure the necessary support of the nobility of León. On December 11, 1230, the Concordia de Benavente was agreed upon, a treaty by which the princesses renounced their claim to the throne in favor of Ferdinand in exchange for financial compensation.

Ferdinand was crowned in León Cathedral on November 7, 1230. Following this unpredictable turn of events, the kingdoms of Castile and León were reunited under the authority of a single monarch, as had been the case between 1072 and 1157, but this time permanently. The new monarch of two illustrious kingdoms, who had married a woman of imperial lineage, Beatrice of Swabia, in 1219, was poised to lead a reign unlike any other in the history of Spain.

This is a crucial period for understanding the origins of the Crown of Castile and León and the development of a monarchical ideology for Spain; it encompasses the most successful phase of the Christian reconquest of the Iberian Peninsula, marked by the annexation of the Almohad kingdoms of Jaén, Córdoba, and Seville. Praised in his epitaph in Seville Cathedral as the monarch who “conquered all of Spain,” Ferdinand III is the only Hispanic king to have been canonized, and no other king since the Visigoths “had reigned over such a vast territory” (González Jiménez, 2003, p. 20), constituting “the largest political entity on the Iberian Peninsula, the first of the Five Kingdoms” (Estepa, 2021, p. 391).

It is worth considering here the significance of the events described for the history of Spain: the young prince, who faced insurmountable odds in his bid to become heir to his father’s throne, ultimately became king of both his father’s and mother’s kingdoms and the most successful conqueror among all Spanish monarchs during the eight centuries of the Reconquista—the “Athlete of Christ,” as Pope Gregory IX called him.

King Ferdinand traveled with his court to such diverse and remote places to assert the royal presence in the newly annexed territories, expanding the monarch’s travels as never before from Castile to León beginning in 1230 and to Andalusia starting in 1236. His domains stretched from the shores of the Cantabrian Sea in the north to the Guadalquivir River in the south, and from the far reaches of Galicia and the Portuguese border in the west to the gates of Aragon and Navarre in the east; or, as noted in the Primera Crónica General, from the sea at Santander to the sea at Cádiz.

Although this brief introduction to the project does not aim to offer definitive conclusions regarding the travel patterns of Ferdinand III, the interactive visualizations allow us to outline connections between the major milestones of his reign and the court’s travels. In this regard, the king’s presence is evident in Castile between 1217 and 1230, then in León, Galicia, and Asturias between 1231 and 1233, and in Andalusia from 1235 onward, specifically in Córdoba and Jaén between 1244 and 1247, and finally in Seville, where the monarch spent much of the last years of his reign until his death in 1252.

Nearly 200 charters were issued by the royal chancellery while the king was traveling throughout the Kingdom of León following his father’s death in September 1230. No other period in the reign of Ferdinand III exhibits such a high geographical density of documentary issuance, which allows us to follow the monarch and his court day by day. In contrast, it is much more difficult to trace the routes and locate the king when he was engaged in one of the many military campaigns he undertook, precisely because there is no documentation, and we can only rely on the less precise accounts of the chronicles, which date certain events solely by reference to religious holidays.

A rolled charter issued by Ferdinand III in Burgos in 1228. It still bears the attached lead seal.

According to José Manuel Nieto Soria’s study, “the reign of Ferdinand III was marked by extraordinary mobility on the part of the royal court,” and the monarch’s presence in all the regions comprising his domains implied “a certain role in integrating diverse territories” and “a strong and close link between governmental action and royal charisma, as a direct relationship was observed between the king’s travels and ongoing conflicts.” (2003, pp. 44–45).

“The best way […] to pacify the kingdom and restore order was to tour it in order to make himself known to his new subjects and receive from them the proper homage of loyalty,” explains Manuel González Jiménez regarding the journey made by Ferdinand III to León in 1230 (op. cit. 127). The royal tour was one of the most effective mechanisms for political cohesion in the region, as well as an undertaking aimed at securing recognition of and allegiance to royal authority. Fernando III’s claims to the thrones of Castile in 1217 and León in 1230, along with the king’s rapid and intense travels to those kingdoms, allow us to link the monarchy’s movements to the major political events of the reign, which can be visualized using the dynamic map of this project.

As for the royal presence in cities, Burgos is the city where the most documents were issued, with a total of 182 charters—that is, more than 21% of the total (852)—followed by Valladolid (113, 13.3%), Seville (86, 10.1%), and Toledo (77, 9%). This distribution reflects phenomena well-known to historians, such as Burgos’s status as the historical capital of the Kingdom of Castile, the gradual shift of the political center to Valladolid between the 13th and 14th centuries, Seville’s prominence as the king’s most prized conquest, as well as Toledo’s ecclesiastical primacy and Visigothic grandeur. The city on the Tagus River was visited by King Ferdinand more frequently than is recorded in the charters, as it served as the starting and returning point for nearly all the military campaigns the monarch waged against Andalusia—a period during which the issuance of documents was suspended.

Carlos Estepa has studied the geographical distribution of the documentary output of Alfonso VIII and Ferdinand III and the beneficiaries of royal generosity, noting that nearly 40% of the documents issued between 1217 and 1252 were issued and witnessed in Castile, while nearly 57% of the recipients were located north of the Duero River (Estepa, 2021, pp. 72, 76).

These are significant data points that demonstrate a certain political centrality despite the territorial expansion that occurred with the union of the kingdom with León and Ferdinand’s Reconquista between the Guadiana and the Guadalquivir. The dynamic maps of this project provide an interactive digital cartography that addresses many other aspects and dimensions of the court’s itinerancy and the territorial deployment of monarchical authority, as well as data that allow for the quantification of human movement in the Middle Ages. The research possibilities these computational statistics open up for historiography are as unexpected as they are unprecedented.

A military unit at that time could cover an estimated 25 kilometers on the march, according to a study of the campaign led by Ferdinand III to conquer Quesada in 1224 (Eslava, 1987, p. 10), but this distance is more of a maximum that would be unsustainable over consecutive days. In a 13th-century military campaign, logistics, provisions, fatigue, the weather, and a variety of other circumstances would have determined the pace of the troops, which normally would not have exceeded 20 kilometers per day.

The feast of St. John the Baptist (June 24) was a date around which military campaigns were launched. It was the summer season that traditionally marked the start of military activity in the Middle Ages, “when kings usually went out to battle,” as noted in the Latin Chronicle of the Kings of Castile (from Osma, p. 77), because winter presented many difficulties. When, in January 1236, some emissaries tried to convince Ferdinand III to march on Córdoba to conquer it, the monarch initially resisted, “citing the harshness of winter […], the dangers of the roads, and the flooding of the rivers,” as de Osma himself notes in his chronicle (op. cit., p. 98).

Ferdinand III, as depicted in a miniature from Tumbo A of the Cathedral of Santiago de Compostela (13th century).

Alfonso IX of León died on September 24, 1230, and when his son, the King of Castile, heard the news at Guadalerzas Castle or in Orgaz—just a few kilometers from Toledo—he organized a journey to León with his mother, Berenguela, to claim the throne. Such was Ferdinand III’s urgency to be recognized as the legitimate heir by the nobility and the cities of the Kingdom of León that, departing from Jaén on September 29 and arriving in Toro on October 18, he traveled more than 550 kilometers according to the itinerary detailed in the Latin Chronicle of the Kings of Castile. Likewise, the king traveled more than 600 kilometers in approximately 21 days from Benavente to Córdoba during the rainy winter of 1236 to besiege the city on the Guadalquivir. In other words, both journeys indicate an average of nearly 29 kilometers per day, a remarkable pace considering the stops and vicissitudes of the journey.

However, following the conquest of Córdoba and up until the siege of Jaén in 1245, the king’s movements became much more sporadic, as he spent long periods in Castile (particularly in Toledo, Burgos, and Valladolid), afflicted by illness and the physical toll of the intense military campaigns he had waged so frequently between 1224 and 1236. His son, Prince Alfonso, and the nobles of Castile and León would take the initiative in the 1240s.

Ferdinand III was one of the most traveled monarchs among the kings of medieval Spain, and he might have lived many more years, but such constant travel took a physical toll on him and greatly affected his health. As one of his biographers notes, the king was “personally involved in most of the operations; he was present during long, arduous, and perilous sieges […]; enduring the cold and the heat; and sacrificing his health in the camps and on long rides” (González Jiménez, 2006, p. 276). After sixteen months of siege and enduring hellish heat, according to the Primera Crónica General, the king gathered his last forces to conquer Seville in 1248, where he remained almost immobile until his death four years later.

“The Final Days of Ferdinand III the Saint” (1887) by Virgilio Mattoni.

All of these events, which defined his reign, offer a fascinating framework for studying the monarchy’s patterns of movement and analyzing royal itineraries using the tools of the Digital Humanities.

A multidisciplinary team from the Humanities Laboratory at the University of San Sebastián, composed of José Manuel Cerda (medieval historian) and Sebastián Caro (digital humanist), has developed, in collaboration with the Fundación Valores CyL, a groundbreaking research project that uses computer programming with Digital Humanities tools and methodology to analyze the travels of medieval kings, generating interactive and open-access visualizations of maps showing their movements throughout the kingdom and offering search options by month, year, and corresponding location.

Professor Cerda’s work has consisted of establishing the project’s framework, defining the parameters for analyzing historical sources, and compiling locations based on various textual sources, while professor Caro has been responsible for creating and organizing the databases, as well as for the programming required for the computational analysis and visualization of the data. Professor Félix Martínez Llorente (University of Valladolid) has provided invaluable assistance in identifying certain place names recorded in the sources whose locations presented various challenges, either because they are abandoned settlements or because their names or locations have changed over time. Chloe Brodie, a student at IE University (Spain), dedicated her internship as a research assistant at the Humanities Lab to conducting a comprehensive review of the website and suggesting improvements for users.

A systematic and comprehensive approach was used to create the database on the whereabouts of King Ferdinand III. The primary source was the collection of royal charters compiled by Julio González, which includes a total of 852 documents (consistent with the count by Manuel González Jiménez (2006, p. 24)), issued between 1217 and 1252. This collection of charters made it possible to locate the monarch throughout his reign in the territories under his rule.

'Las quatro partes enteras de la Coronica de España, que mando componer el rey don Alonso llamado el Sabio' (13th century).

Throughout the process, a variety of medieval narrative sources and historiographical works have also been examined, providing new insights into the royal itinerary. Among these are the Latin Chronicle of the Kings of Castile by Juan de Osma (chancellor to Ferdinand III), as well as the Annals of Toledo, the History of the Deeds of Spain by Rodrigo Jiménez de Rada, The General Chronicle of Spain, the Chronicon Mundi (Chronicle of Spain) by Lucas de Tuy, and the Chronicle of Twenty Kings. These works were written during the reigns of Ferdinand III and his son Alfonso X the Wise, and they allow us to corroborate the locations provided by the diplomatary and add new records to the database.

These sources allow us to track the king’s movements during his military campaigns, such as the attack on several Castilian rebel strongholds in 1217, the capture of castles northeast of Úbeda in the summer of 1235, the conquest of Córdoba in 1236, and the siege of Seville between 1247 and 1248, during which we can pinpoint the location of the monarch and his troops on a day-to-day basis. By far, the prose that provides the most georeferenced data on Ferdinand III’s itinerary is the chronicle of Juan de Osma, which is not surprising given that he headed the royal chancellery and accompanied the king on many of his journeys (M. González Jiménez, 2006, 14–15).

In addition, the itinerary included the royal presence at weddings, ceremonies, and assemblies, based on information provided by the chronicles, which is not always found in the diplomatic records.

Once the sources of information regarding the locations from which Ferdinand III’s chancellery issued diplomas had been identified, the data was entered into a spreadsheet. Each location was properly geolocated according to its latitude, longitude, and altitude, named using its original name in the texts—generally in Latin—and its level of authenticity was established. During the reign of Ferdinand III, there was a transition from Latin to Castilian in chancery usage, which has posed certain challenges in toponymic identification. Some of the many cases are Castrum Soris - Castrum Soriz - Castrosoriz - Castrum Xoriz - Castrum Xesit (Castrojeriz); Naiara - Naiera - Naigara - Naggera - Nazara - Naxara - Najera (Nájera); Vallis Oliuetion - Vallisoletum - Vallesoletum - Valleolitin - Valadolid - Valladolit - Valladolid.

A consolidated spreadsheet listing King Ferdinand III’s visit locations, their geographic coordinates, and historical and geographic notes.

It has also been necessary to cross-check, verify, and—in some cases—correct the locations of the documents transcribed in Julio González’s collection. A case in point is the mention that in August 1218, Ferdinand III apud Medinam (Medina de Rioseco), when the correct transcription is apud Carrionem (Carrión de los Condes), and a few days later, the king granted a charter to a hospital in Santo Domingo de Silos facta apud Medinam, whereas in González’s register it is incorrectly located in Montealegre. The dating in the text is also incorrect.

To accurately pinpoint the king’s whereabouts, we used transcriptions of documents from other collections, as well as the logical consistency between dates and distances traveled. This process was also aided by works such as Atlas Histórico de la España Medieval and historical geographical dictionaries of Spain, such as Madoz’s Diccionario Geográfico-Estadístico-Histórico de España and the Diccionario Geográfico-Histórico de España by the Royal Academy of History. At this stage of the project, difficulties have also arisen in identifying places whose names in the sources show inconsistencies or alterations, or in cases involving abandoned settlements.

Hispaniae Descriptio [Description of Spain] by Vincentius Luchini (Rome, 1559).

The lack of documentation and tracking of the monarch and his court in the chronicles also poses a challenge for this project. There are some years in which several months pass without any information regarding the king’s whereabouts; consequently, the maps and itineraries do not provide conclusive evidence regarding his routes or patterns of movement. In some cases, the lack of activity in the chancellery indicates extensive military campaigns that can be traced with the help of the chronicles. But the information provided by the narrative—even when it comes from chroniclers who were regulars at court and accompanied the monarch on his travels—is generally ambiguous and imprecise.

When historical records do not specify exact dates—as is the case in the vast majority of instances—we have determined the royal presence on an estimated date based on the itinerary outlined in the official documents. In such cases, this date is listed in parentheses in the database and in the visualizations to alert the user that it is an estimated date. Information regarding these dates and locations is included in the notes column of the database.

The project’s digital historical maps were created using QGIS software, based on a cartographic construction process that drew on historiographical sources and spatial interpretation criteria. First, cartographic and historical records regarding the territorial configuration of the peninsular kingdoms during the reign of Ferdinand III were compiled and analyzed, focusing on three key moments: 1217 (the beginning of his reign in Castile), 1230 (the union of the crowns of Castile and León), and 1248 (the conquest of Seville). On this basis, the territorial boundaries were digitized by creating polygon-type vector layers, manually delineated in QGIS based on a comparison between historical maps and current georeferenced cartography. Each territorial unit was recorded in an attribute table that allowed for its identification and classification, subsequently facilitating the application of differentiated symbology through categorized styles. Likewise, labels with the names of the kingdoms were incorporated, with their position and legibility adjusted according to the geometry of each polygon. As a visual aid, a contemporary base map was integrated to spatially contextualize the historical entities, applying transparency levels to balance the visualization. The final result consisted of three thematically comparable maps, constructed according to uniform representation criteria, which allow for the visualization of the territorial evolution of Ferdinand III’s power on the Iberian Peninsula, while acknowledging at all times the interpretive nature of medieval borders.

Digital map of the Iberian kingdoms created in QGIS, showing the territorial division during the reign of Ferdinand III.

The computational deployment phase of the project involves an application developed on the R platform using the Shiny package, which enables the interactive generation of geospatial data visualizations. The application retrieves information from the database established in the previous phase, performs data type validation checks, and adjusts formats based on the structure of geographic coordinates and dates.

The project's pivot table was developed as an interactive web application using the R programming language, leveraging the Shiny framework in combination with the reactable, data.table, and htmltools libraries. The primary data source is a spreadsheet file containing documented records of Ferdinand III’s itinerary between 1217 and 1252, with fields including day, month, year, place, original place name, geographic coordinates (latitude, longitude, and altitude), documentary source, and critical status of the record. During data loading, normalization and cleaning routines were applied to standardize textual values with orthographic variations, remove markers of uncertainty such as square brackets and question marks, and convert date and location fields to comparable formats for sorting and filtering.

The resulting application was built using the reactable package, configured with pagination, column sorting, and responsive display. A specific feature manages the original place name column, allowing users to expand or collapse the text by directly interacting with the cell. The filter system includes four search dimensions: date range, month selection, year range, and location selection, all of which can be used simultaneously and reset using a dedicated button. The color coding of the rows reflects the critical status of each record according to Julio González’s classification: orange for conjectured dates and locations, yellow for records listed in the index but not counted, and red for documents considered suspicious, false, dubious, or forged. Finally, the application includes an interactive introductory tutorial based on the rintrojs library, which guides the user through the main components of the interface upon first access.

Pivot table showing Fernando III's itinerary, with filters for date and location, and rows colored by critical status.

The project’s interactive map visualization was developed as a web application in R using the Shiny framework, integrating the libraries leaflet, sf, dplyr, readxl, rnaturalearth, leaflet.extras, htmlwidgets, and rintrojs. Its construction combined, on the one hand, the geographic database of Ferdinand III’s travels, contained in spreadsheet files with information on dates, locations, and coordinates, and, on the other hand, a set of historical vector layers in shapefile format corresponding to three chronological periods of the reign: 1217, 1230, and 1248. These layers were read and transformed into the WGS84 geographic reference system (EPSG:4326), which allowed for their representation in an interactive web environment alongside a base physical map. Based on this structure, the application automatically displays the relevant historical map according to the year—and in the cases of 1230 and 1248, also according to the month—so that the visualization of the borders corresponds to key moments in the territorial evolution of the kingdom.

Overlaid on this map are records of the king’s itinerary, represented by custom markers, pop-up windows with contextual information, hierarchical place labels, and an optional heat map layer that allows users to identify spatial concentrations of visits. The system also includes filters by year, month, and location, as well as a specific feature to trace the monarch’s itinerary using numbered sequential lines that represent the chronological order of the journeys. The interface was complemented with a color-coded legend of the historical kingdoms, layer activation controls, and a guided tutorial implemented with Rintrojs, designed to facilitate exploration of the tool by non-specialist users. The result is a dynamic visualization that integrates temporality, spatiality, and historical analysis, allowing users to interactively track the movements of Ferdinand III in relation to the political transformations of the Iberian Peninsula.

Interactive map of Ferdinand III's itinerary with chronological filters and historical layers.

This Digital Humanities project on royal travel opens the door to a world of analytical possibilities regarding the movement patterns of Ferdinand III and his court throughout their domains. Interacting with the maps provides immediate data on the approximate total number of kilometers traveled by the king in a day, month, year, and throughout his entire reign, as well as the average number of daily trips. It also generates graphs of the elevation of the terrain traveled, which affects the speed and pace of the journeys. But more relevant than that data, the digital map offers visualizations that allow us to understand how the monarch’s presence projected royal authority across the entire territory.

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Eslava Galán, Juan. La campaña de 1225 y el primer cerco de Jaén por Fernando III. Boletín del Instituto de Estudios Giennenses, 132 (1987), 23-38.

Eslava Galán, Juan. La campaña de Quesada (1224). Cuadernos de estudios medievales y ciencias y técnicas historiográficas, 12-13 (1984), 5-23.

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Sirantoine, Hélène. La cancillería regia en época de Fernando III. Ideología, discurso y práctica. Fernando III: tiempo de cruzada, coord. Carlos de Ayala Martínez y Martín Federico Ríos Saloma, Madrid: Sílex, 2012, 175-203.