Editing Alfonso VI of León and Castile (section)

==Life==
===Birth and early years===
The son of [[Ferdinand I of León|Ferdinand I, King of León and Count of Castile]] and his wife, Queen Sancha, Alfonso was a "Leonese ''[[infante]]'' [prince] with Navarrese and Castilian blood".{{Sfn|Martínez Díez|2003|p=19}} His paternal grandparents were [[Sancho III of Pamplona|Sancho Garcés III]], [[List of Navarrese monarchs|king of Pamplona]] and his wife [[Muniadona of Castile]], and his maternal grandparents were [[Alfonso V of León]] (after whom he was probably named) and his first wife [[Elvira Menéndez (died 1022)|Elvira Menéndez]].{{Sfn|Martínez Díez|2003|pp=20–25}}

The year of Alfonso's birth is not recorded in the medieval documentation. According to one of the authors of the ''[[Crónicas anónimas de Sahagún|Anonymous Chronicle of Sahagún]]'', who met the monarch and was present at his death, he died at age 62 after reigning 44 years.{{efn|Some sources give the age in the ''Chronicle of Sahagún'' as 72, which would place his birth in 1037.{{Sfn|Reilly|1989|p=20}}{{Sfn|Salvador Martínez|1992|p=29}}}} This indicates that he was born in the second half of 1047{{Sfn|Salazar y Acha|1993|p=303}} or in the first half of 1048.{{Sfn|Martínez Díez|2003|p=21}} [[Pelagius of Oviedo]] wrote that Alfonso was 79 when he died, but that would place his birth around 1030, before his parents' marriage.{{Sfn|Reilly|1989|p=20}}

According to the ''[[Historia silense]]'', the eldest child of Ferdinand I and Sancha, a daughter called [[Urraca of Zamora|Urraca]], was born when her parents were still [[List of Castilian counts|Count and Countess of Castile]], so her birth could be placed in 1033–34.{{Sfn|Sánchez Candeira|1999|p=226}} The second child and eldest son, [[Sancho II of Castile and León|Sancho]], must have been born in the second half of 1038 or in 1039.{{Sfn|Sánchez Candeira|1999|p=227}} The third child and second daughter, [[Elvira of Toro|Elvira]], may have been born in 1039–40,{{Sfn|Sánchez Candeira|1999|p=227}} followed by Alfonso in 1040–41,{{Sfn|Sánchez Candeira|1999|p=227}} and finally the youngest of the siblings, [[García II of Galicia|García]], sometime between 1041 and 24 April 1043, the date on which King Ferdinand I, in a donation to the [[Abbey of San Andrés de Espinareda]], mentions his five children.{{Sfn|Sánchez Candeira|1999|p=227}} All of them except Elvira signed a document in the monastery of [[San Juan Bautista de Corias]] on 26 April 1046.{{Sfn|Sánchez Candeira|1999|p=227}}

All the children of King Ferdinand I, according to the ''Historia silense'', were educated in the [[Liberal arts education|liberal arts]], and the sons were also trained in arms, the "art of running horses in the Spanish usage", and hunting.{{Sfn|Sánchez Candeira|1999|p=228}} The cleric [[Raimundo I of Palencia|Raimundo]] was in charge of Alfonso's early education. Once king, Alfonso appointed him [[Roman Catholic Diocese of Palencia|Bishop of Palencia]] and referred to him as ''magistro nostro, viro nobile et Deum timenti'' ("our master, a noble man who fears God").{{Sfn|Sánchez Candeira|1999|p=228}} Alfonso probably spent long periods in [[Tierra de Campos]], where, along with [[Pedro Ansúrez]], the son of Ansur Díaz and nephew of Count Gómez Díaz de Saldaña (both members of the [[Banu Gómez]] lineage), he learned the art of war and what was expected of a knight.{{Sfn|Sánchez Candeira|1999|p=228}}

===Ascension to the throne===
As the second son of the king of León and count of Castile,{{Sfn|Sánchez Candeira|1999|p=227}}{{Sfn|Miranda Calvo|1976|p=112}} Alfonso would not have been entitled to inherit the throne.{{Sfn|Martínez Díez|2003|p=19}} At the end of 1063, probably on 22 December, taking advantage of the fact that numerous [[magnate]]s had gathered in [[León, Spain|León]], capital of the kingdom, for the consecration of the [[Basílica de San Isidoro, León|Basílica of San Isidoro]],{{Sfn|Sánchez Candeira|1999|p=229}} Ferdinand I summoned a [[Court (royal)|''Curia Regia'']] to make known his testamentary dispositions, under which he decided to distribute his patrimony among his children, a distribution that would not become effective until the death of the monarch{{Sfn|Martínez Díez|2003|pp=30–33}} in order to prevent any disputes arising after his death:{{Sfn|Sánchez Candeira|1999|p=230}}
[[File:Europe-south-west-kingdoms.png|thumb|left|Political situation in the Northern [[Iberian Peninsula]] around 1065:
{{legend|#ba7f45|[[García II of Galicia|Garcia II]]´s domains (Galicia)}}
{{legend|#68ae94|Badajoz, owing tribute to Garcia}}
{{legend|#329ca7|Seville, owing tribute to Garcia}}
{{legend|#c2a541|Alfonso VI's domains (León)}}
{{legend|#88a756|Toledo, owing tribute to Alfonso}}
{{legend|#dcc983|[[Sancho II of León and Castile|Sancho II]]´s domains (Castile)}}
{{legend|#c0bf78|Zaragoza, owing tribute to Sancho}}]]
*Alfonso inherited the [[Kingdom of León]],{{Sfn|Sánchez Candeira|1999|p=230}} "the most extensive, valuable and emblematic part: the one that contained the cities of [[Oviedo]] and [[León, Spain|León]], cradles of the Asturian-Leonese monarchy",{{Sfn|Martínez Díez|2003|p=19}} which included [[Asturias]], León, [[Astorga, Spain|Astorga]], [[El Bierzo]], [[Zamora, Spain|Zamora]] with [[Tierra de Campos]] as well as the ''[[parias]]'' of the [[Taifa of Toledo]].{{Sfn|Martínez Díez|2003|pp=31–33}}
*His elder brother, [[Sancho II of Castile and León|Sancho]], was given the [[Kingdom of Castile]], created by his father for him, and the ''parias'' of the [[Taifa of Zaragoza]].{{Sfn|Sánchez Candeira|1999|p=230}}{{Sfn|Martínez Díez|2003|p=31}}{{refn|group=lower-alpha|"Despite being the eldest son, Sancho received, in terms of territory, the smallest part, a very mutilated Castile, while León —to which the royal title was attached— with the most extensive lands, was assigned to the second of the brothers, Alfonso, as if he was the favorite child".{{Sfn|Martínez Díez|2003|p=33}}}}
*His younger brother, [[García II of Galicia|García]], received the entire region of [[Kingdom of Galicia|Galicia]], "elevated to the rank of kingdom"{{Sfn|Martínez Díez|2003|p=33}} that extended south to the [[Mondego River]] in [[Portugal]] with the ''parias'' of the [[Taifa of Badajoz]]{{Sfn|Martínez Díez|2003|p=33}} and [[Taifa of Seville|Seville]].{{Sfn|Sánchez Candeira|1999|p=231}}
*Their sisters, [[Urraca of Zamora|Urraca]] and [[Elvira of Toro|Elvira]], both received the ''Infantazgo'', that is, "the patronage and income of all the monasteries belonging to the royal patrimony"{{Sfn|Martínez Díez|2003|p=33}} on the condition that they remained unmarried.{{Sfn|Sánchez Candeira|1999|p=231}}

The historian Alfonso Sánchez Candeira suggests that the reasons leading King Ferdinand I to divide the kingdom (with Alfonso VI inheriting the royal title) are unknown, but the distribution was probably made because the king considered it proper that each son should inherit the region where he had been educated and spent his early years.{{Sfn|Sánchez Candeira|1999|p=231}}

===Reign===
====Consolidation of the throne (1065{{ndash}}1072)====
After his coronation in the city of León in January 1066, Alfonso VI had to confront the expansionist desires (although Alfonso would prove himself as having the same or more so) of his brother Sancho II, who, as the eldest son, considered himself the sole legitimate heir of all the kingdoms of their father.{{Sfn|Martínez Díez|2003|p=35}} The conflicts began after the death of their mother Queen Sancha on 7 November 1067,{{Sfn|Martínez Díez|2003|p=36}} leading to seven years of war among the three brothers. The first skirmish was the [[Battle of Llantada]],{{Sfn|Martínez Díez|2003|pp=36–37}} a [[trial by ordeal]] in which both brothers agreed that the one who was victorious would obtain the kingdom of the defeated brother. Although Sancho II was the winner, Alfonso VI did not comply with the agreement; even so, relations between them remained cordial as evidenced by the fact that Alfonso was present at the wedding of Sancho II to an English noblewoman named Alberta on 26 May 1069. This was the same event where both decided to join forces to divide between themselves the Kingdom of Galicia that had been assigned to their younger brother García II.{{citation needed|date=July 2019}} In the wake of the fratricidal war waged between the successors of al-Muzaffar, ruler of the taifa of Badajoz, upon the latter's death in 1068, Alfonso managed to exploit the situation in order to extract economic profit, even though the taifa nominally fell under García's sphere of influence.{{Sfn|Ayala|2013|pp=229–230}}

With the complicity of Alfonso VI, Sancho II invaded Galicia in 1071,{{Sfn|Martínez Díez|2003|p=38}} defeating their brother García II who was arrested in [[Santarém, Portugal|Santarém]] and imprisoned in [[Burgos]] until he was exiled to the [[Taifa of Seville]], then under the rule of [[Al-Mu'tamid ibn Abbad]]. After eliminating their brother, Alfonso VI and Sancho II titled themselves kings of Galicia and signed a truce.{{Sfn|Reilly|1989|p=9}}

The truce was broken with the [[Battle of Golpejera]] on 12 January 1072.{{Sfn|Martínez Díez|2003|p=38}} Although Sancho II's troops were victorious, he decided not to persecute his brother Alfonso, who was imprisoned in Burgos{{Sfn|Martínez Díez|2003|p=39}} and later transferred to the monastery of Sahagún, where his head was shaved and he was forced to wear a [[chasuble]]. Thanks to the intercession of their sister Urraca, Sancho and Alfonso reached an agreement under which Alfonso VI was able to take refuge in the [[Taifa of Toledo]] under the protection of his vassal [[Al-Mamun of Toledo|Al-Mamun]], accompanied by his childhood friend, the faithful Pedro Ansúrez and his two brothers Gonzalo and Fernando.{{Sfn|Martínez Díez|2003|pp=40–41}}

Alfonso VI, from his exile in Toledo, obtained the support of the Leonese nobility and his sister Urraca, who remained strong in the city of Zamora, a lordship that Ferdinand I had granted her previously.{{Sfn|Martínez Díez|2003|p=41}} When Urraca refused to exchange Zamora for other cities that Sancho had offered her in an effort to control the fortress of Zamora, "key to the future expansion south of the [[Douro|Duero]]", Sancho besieged the city.{{Sfn|Martínez Díez|2003|p=41}}  However, during the siege, Sancho II was murdered. According to tradition, during the siege a nobleman named Vellido Dolfos appeared before the king, claiming to have changed his loyalty from Urraca to Sancho. Under the pretense of showing him the weak parts of the city's walls, Dolfos separated the king from his guard and killed him with a spear.{{Sfn|Martínez Díez|2003|p=43}} Although there is no clear evidence that Sancho II's death was due to treason rather than deceit, since Dolfos was Sancho II's enemy, his murder occurred in a warlike attack during the siege, not near the city walls, but rather in a nearby forest where Dolfos lured the Castilian king away from his armed protection.{{Sfn|Reilly|1989|p=9}} The violent death of Sancho II, who had no descendants, allowed Alfonso VI to reclaim his throne as well as Sancho's and Garcia's original inheritances of Castile and Galicia, respectively.{{Sfn|Reilly|1989|p=9}}

Although [[El Cid|Rodrigo Díaz de Vivar]] (El Cid), the [[standard-bearer]] and confidant of King Sancho II, was present at the siege of Zamora, the role he played in this event is not known. Neither can Sancho II's death be blamed on Alfonso VI, who, when his brother was killed, was in exile far from the events.{{Sfn|Martínez Díez|2003|p=44}} However, this did nothing to prevent speculation that Alfonso was somehow involved in Sancho's murder; despite a paucity of evidence, "minstrels and ballads filled this void with beautiful literary creations devoid of any historical reality".{{Sfn|Martínez Díez|2003|p=44}}

The lingering suspicion over this event would later become part of the ''Leyenda de Cardeña'', a set of legendary narrative materials concerning El Cid which began to develop in the 13th century.<ref>{{cite book |last= Peña Pérez|first=F. Javier |date=2003 |chapter= Los monjes de San Pedro de Cardeña y el mito del Cid|title= Memoria, mito y realidad en la historia medieval|trans-title=Memory, Myth and Reality in Medieval History |url=https://dialnet.unirioja.es/descarga/articulo/814545.pdf
|language=EN |location= Logroño|publisher=Instituto de Estudios Riojanos |isbn=84-95747-55-3|pages=340–343}}</ref>

According to legend, Alfonso VI was forced by El Cid to take an oath denying that he had been involved in his brother's death, thus giving rise to mutual distrust between the two men, despite Alfonso VI's efforts at rapprochement by offering his kinswoman [[Jimena Díaz]] to El Cid in marriage as well as the immunity of his patrimony. These events and their consequences would eventually come to be considered historical by many later chroniclers and historians; however, most modern historians deny that such an event ever took place.{{Sfn|Martínez Díez|2003|pp=47–48}}

Thanks to Sancho II's death, García II could regain his own throne of Galicia; however, the following year, on 13 February 1073,{{Sfn|Reilly|1992|p=74}}{{Sfn|Martínez Díez|2003|p=49}} Alfonso summoned García to a meeting, whereupon he imprisoned his younger brother. Garcia was held at the castle of Luna for seventeen years, where he eventually died on 22 March 1090.{{Sfn|Martínez Díez|2003|p=49}} With his two brothers out of the way, Alfonso VI was able to secure the loyalty of both the high clergy and the nobility of his territories with ease; to confirm this, he spent the next two years visiting them.{{Sfn|Reilly|1992|p=74}}

====Territorial expansion (1072{{ndash}}1086)====
Now established on the Leonese throne, and with the title of "Emperor", a relic of the [[Goths#Visigoths|Gothic]] tradition, Alfonso VI spent the following fourteen years of his reign expanding his territories through conquests such as that of [[Uclés]] and the lands of the Banu Di-l-Nun family. In 1072 he entitled himself ''rex Spanie''.{{Sfn|Luis Corral|2012|pp=1–40}}

[[File:Alfonso VI of Castile.jpg|thumb|left|Alfonso in the ''[[Libro de las Estampas]]'']]

In 1074, in alliance with [[Al-Mamun of Toledo|Al-Mamun]], ruler of the Taifa of Toledo, Alfonso waged an offensive against the Zirid ruler of the [[Taifa of Granada]], [[Abdallah ibn Buluggin|Abd Allâh]], taking the strategic fortress of [[Alcalá la Real]].{{Sfn|Ayala|2013|p=230}}

Following the assassination of [[Sancho IV of Navarre]] in 1076, leaving only minor sons, the local Navarrese nobility divided over the succession to the Navareese crown. Alfonso VI had immediately taken possession of Calahorra and Najera, and also received the support of the nobility of [[Biscay|Vizcaya]]-[[Álava]] and [[La Rioja]], while the eastern nobility supported [[Sancho Ramírez|Sancho Ramírez of Aragon]], who moved into the remainder of the kingdom.{{sfn|Martín Duke}} After the two kings reached an accord, Sancho Ramírez was recognized as king of Navarre and Alfonso VI annexed the territories of [[Álava]], [[Biscay|Vizcaya]], part of [[Gipuzkoa|Guipúzcoa]] and [[La Bureba]], adopting in 1077 the title of ''[[Imperator totius Hispaniae]]'' ("Emperor of all Spain").{{Sfn|Mínguez Fernández|2009|pp=30–33}}

His great territorial expansion came at the expense of the [[Taifa]] Muslim kingdoms. Alfonso VI continued their economic exploitation by means of the system of ''parias'', and succeeded in subduing most of the Taifa kingdoms as his tributaries, enforced by the threat of military intervention. In 1074, he probably recovered payment of the ''parias'' of Toledo, and the same year, helped by troops of that city, he cut down trees on the lands of the [[Taifa of Granada]], which consequently also began to pay him taxes.{{Sfn|Reilly|1992|p=75}} In 1076, the Emir of Zaragoza, who wished to seize Valencia without being disturbed by Alfonso VI, agreed to resume payment of the ''parias''.{{Sfn|Reilly|1992|pp=74–75}} In 1079, he conquered [[Coria, Cáceres|Coria]].{{Sfn|Guichard|1989|p=496}}

One of the initiatives of these years, known as the "Treason of Rueda", ended in failure. It took place in 1083 in the castle of [[Rueda de Jalón]], when Alfonso VI received news that the governor of that stronghold, which belonged to the Taifa of Zaragoza, intended to surrender it to the Leonese king. The king's troops were ambushed when they entered the castle and several of the most important magnates of the kingdom were killed.{{Sfn|Martínez Díez|2007|pp=134–137}}{{Sfn|Montaner Frutos|1998|pp=32–38}}

In 1074, Alfonso VI's vassal and friend Al-Mamun, king of the Taifa of Toledo died of poisoning in [[Córdoba, Spain|Córdoba]], and was succeeded by his grandson Al-Qádir, who asked for help from the Leonese monarch to end an uprising against him. Alfonso VI took advantage of this request to besiege Toledo, which finally fell on 25 May 1085. After losing his throne, Al-Qádir was sent by Alfonso VI as king of the [[Taifa of Valencia]] under the protection of [[Álvar Fáñez]]. To facilitate this operation and to recover payment of the ''parias'' owed by the city, which had failed to pay him since the previous year, Alfonso VI besieged Zaragoza in the spring of 1086.{{Sfn|Reilly|1992|pp=86–87}} In early March, Valencia accepted the rule of Al-Qádir; [[Xàtiva]] resisted requesting the aid of the rulers of Tortosa and Lérida until he was forced to do so. Their raid of the region failed, and they withdrew under harassment by the troops of Fáñez.{{Sfn|Reilly|1992|p=75}}

After this important conquest, Alfonso VI was entitled [[Emperor of the Two Religions|''al-Imbraţūr dhī-l-Millatayn'' ("Emperor of the Two Religions")]] and as a gesture to the important Muslim population of the city, he promised them, in addition to respecting their properties, the right to use the main mosque. This decision was later revoked by the newly appointed [[archbishop of Toledo]], [[Bernard of Sédirac]], who took advantage of the king's absence from Toledo and with the support of [[Constance of Burgundy|Queen Constance]].{{citation needed|date=June 2022}}

The occupation of Toledo—which allowed Alfonso VI to incorporate the title of King of Toledo with those he already used ({{lang|la|victoriosissimo rege in Toleto, et in Hispania et Gallecia}}<ref name="Vicente"/>)—led to the taking of cities such as [[Talavera de la Reina|Talavera]] and fortresses including the castle of [[Aledo, Murcia|Aledo]]. He also occupied Mayrit (now [[Madrid]]) in 1085 without resistance, probably by capitulation. The incorporation of the territory situated between the [[Sistema Central]] and the [[Tagus|Tajo]] river would serve as the base of operations for the Kingdom of León, from where he could launch more attacks against the [[Taifa of Córdoba|Taifas of Cordoba]], [[Taifa of Seville|Seville]], [[Taifa of Badajoz|Badajoz]] and [[Taifa of Granada|Granada]].<ref name="Vicente"/>

====Almoravid invasions (1086{{ndash}}1109)====
The conquest of the extensive and strategic Taifa of Toledo, the control of Valencia and the possession of Aledo, which isolated [[Murcia]] from the rest of [[Al-Andalus]], worried the Muslim sovereigns of the [[Iberian Peninsula]].{{Sfn|Reilly|1992|p=87}} The military and economic pressure on the Taifa kingdoms led the rulers of the Taifas of Seville, Granada, Badajoz, and Almeria to seek help from [[Yusuf ibn Tashfin]], the [[Almoravid dynasty|Almoravid]] Emir who ruled the Maghreb.{{Sfn|Guichard|1989|p=500}} At the end of July 1086, Almoravid troops crossed the [[Strait of Gibraltar]] and landed in [[Algeciras]].{{Sfn|Reilly|1992|p=88}}

In Seville, the Almoravid army joined the troops of the Taifa kingdoms, and together they marched to [[Extremadura]]. There, on 23 October 1086,{{Sfn|Huici Miranda|1954|p=42}} they faced the troops of Alfonso VI (who had to abandon the siege of Zaragoza) in the [[Battle of Sagrajas]].{{Sfn|Reilly|1992|pp=88, 110}} Álvar Fáñez, who had been called from Valencia, came and joined the king's forces.{{Sfn|Reilly|1992|p=88}} The battle ended with the defeat{{Sfn|Huici Miranda|1954|p=41}} of the Christian troops,{{Sfn|Guichard|1989|p=500}} who returned to Toledo to defend themselves. The Emir, however, did not take advantage of the victory since he had to rush back to Africa because of the death of his son.{{Sfn|Reilly|1992|p=89}} The defeat marked the beginning of a new era in the Iberian Peninsula that lasted about three decades, in which the military initiative was taken by the Almoravids and Alfonso VI had to remain on the defensive. Nevertheless, he was able to retain Toledo, the main target of the Almoravid attacks.{{Sfn|Reilly|1992|p=89}}

Alfonso VI asked the Christian kingdoms of Europe to organize a Crusade against the Almoravids, who had recovered almost all the territories he had conquered, with the exception of Toledo, where the king remained strong. To reinforce his position, he reconciled with [[El Cid]], who came to Toledo in late 1086 or early 1087.{{Sfn|Huici Miranda|1954|p=41}} As a consequence of the serious defeat, the Andalusian taifas stopped paying the ''parias''.{{Sfn|Huici Miranda|1954|p=41}} The Cid, however, succeeded in re-subjugating the rebel Taifas over next two years.{{Sfn|Huici Miranda|1954|p=49}}

Even though the crusade did not finally materialize, a large number of foreign knights came to the Iberian Peninsula. They included [[Raymond of Burgundy|Raymond]] and [[Henry, Count of Portugal|Henry of Burgundy]], who married Alfonso VI's daughters [[Urraca of León|Urraca]] (1090) and [[Teresa of León, Countess of Portugal|Teresa]] (1094), respectively, which led to the establishment of the [[Anscarid]] and [[House of Burgundy|Capetian]] dynasties in the peninsular kingdoms.{{Sfn|Reilly|1992|p=90}} Some of the crusaders unsuccessfully besieged [[Tudela, Navarre|Tudela]] in the winter of 1087, before withdrawing.{{Sfn|Huici Miranda|1954|p=41}}{{Sfn|Reilly|1992|pp=89–90}} That same year, the king crushed a revolt in Galicia aimed at releasing his brother García II.{{Sfn|Reilly|1992|pp=90–91}}

In 1088 Yusuf ibn Tashfin crossed the [[Strait of Gibraltar]] for the second time, but was defeated at the siege of Aledo and suffered the desertion of many of the rulers of the taifas. When the emir came again to the peninsula, he decided to depose all the taifa rulers and became the sole king of the entire Al-Andalus territory.{{Sfn|Reilly|1992|p=91}} Thanks to the Muslim defeat in Aledo, Alfonso VI had been able to resume the collection of the ''parias'' by threatening the ruler of the city that he would chop all the trees in the territory of Granada and then went to Seville to subjugate the city again.{{Sfn|Huici Miranda|1954|p=45}} [[Abdallah ibn Buluggin]] of Granada had distanced himself definitively from Yusuf ibn Tashfin and Alfonso VI promised to help him in exchange for his submission.{{Sfn|Huici Miranda|1954|pp=45–46}}

In June 1090, the Almoravids launched a third attack, deposed the king of Granada, defeated the governor of Córdoba, and after the Battle of [[Almodóvar del Río]], entered Seville and sent King al-Mutamid into exile.{{Sfn|Huici Miranda|1954|p=42}} In the second half of the year, all the southern taifas had been conquered by the Almoravids and Alfonso was not able to fulfill his promise to help the king of Seville.{{Sfn|Reilly|1992|p=91}} The king suffered setbacks on all fronts: in the east he failed to seize [[Tortosa]] due to the late arrival of the Genoese fleet that was to take part in its capture; further south, Al-Qádir was deposed in a revolt; in the south, his relation with Zaida, daughter-in-law of the king of Seville failed to enhance his image as the champion of the Muslims of the peninsula against the Almoravids; and, finally, in the west, the alliance with the king of Badajoz did not stop the North Africans from conquering this territory.{{Sfn|Reilly|1992|p=92}} As the price for this alliance, Alfonso VI had obtained [[Lisbon]], [[Sintra]], and [[Santarém, Portugal|Santarém]], but lost them in November 1094 when his son-in-law Raymond of Burgundy, responsible for defending these cities, was defeated by the Almoravid army that had taken Badajoz shortly before.{{Sfn|Reilly|1992|p=92}} The only good news for Alfonso VI was the recovery of Valencia in June by El Cid, who had defeated the Almoravid army that had advanced against him in the [[Battle of Cuarte]] on 21 October. This victory set the eastern border for about a decade.{{Sfn|Reilly|1992|p=92}}

According to some historians, Alfonso VI later defeated a conspiracy of his sons-in-law Raymond and Henry who had plotted to divide the kingdom at his death.{{Sfn|Reilly|1992|p=93}} To turn them against each other, he gave Henry and Teresa the government of the [[County of Portugal]],{{Sfn|Reilly|1992|p=93}} until then ruled by Raymond, which comprised the lands from the [[Minho (river)|Minho]] river to Santarém, while the government of Raymond was limited to Galicia.{{Sfn|Martínez Díez|2003|pp=170–171}} Other scholars, however, have shown that the pact could not have been made before 1103,{{Sfn|David|1948|pp=275–276}}{{Sfn|Bishko|1971|pp=155–188}} suggesting instead that Henry's appointment was made in response to the military defeat of 1094.

[[File:AlfonsoVIsign.jpg|thumb|250px|left|Signature of Alfonso VI, from a 1097 charter.]]
In 1097, there was a fourth Almoravid invasion.{{Sfn|Reilly|1992|p=93}} Alfonso received the news when he was on his way to Zaragoza to assist his vassal [[Al-Mustain II]] in his confrontation with King [[Peter I of Aragon and Navarre]]. Once again, the Almoravid objective was Toledo,{{Sfn|Reilly|1992|p=93}} and they defeated the Christian forces at the [[Battle of Consuegra]] on 15 August, thus confirming the decline of the reign of Alfonso VI that had begun in 1086 with the defeat at Sagrajas.

In 1099, the Almoravids conquered a large number of the castles that defended Toledo and the surrounding areas and, in the following year, they tried unsuccessfully to seize the city.{{Sfn|Reilly|1992|p=94}} Henry of Burgundy, Alfonso's son-in-law, was in charge of defending Toledo since the king, at that time, was in Valencia inspecting its defenses. El Cid had died the previous year and his widow, Jimena, was governing the city.{{Sfn|Reilly|1992|p=94}}

In 1102, Alfonso VI sent troops to help Valencia against the Almoravid threat.{{Sfn|Reilly|1992|p=94}} The battle took place in [[Cullera]] and ended without a clear winner, although Valencia fell into Almoravid hands regardless because Alfonso decided it was too expensive to defend.{{Sfn|Reilly|1992|p=94}} Alfonso VI supervised the evacuation of Valencia in March and April and set fire to it before leaving; in May, the Almoravids took possession of the remains.{{Sfn|Reilly|1992|p=94}} The same year, he undertook the repopulation of Salamanca, which protected Coria, and Ávila, which defended the mountain pass that was more accessible from Guadarrama, trying to prepare for an eventual loss of Toledo.{{Sfn|Reilly|1992|pp=94–95}} To protect the area from the east, in 1104 he besieged and conquered [[Medinaceli]], a key location from which the region of Toledo could be attacked from the east along the valley of the [[Jalón (river)|Jalón River]].{{Sfn|Reilly|1992|p=95}} In 1104, 1105, and 1106, the king made several incursions into Andalusian territory, reaching [[Málaga]] in 1106, and returned with many [[Mozarabs]], who settled in his kingdom.{{Sfn|Reilly|1992|p=95}}

In 1108 the troops of the Almoravid Tamim, governor of Córdoba and son of Yusuf ibn Tashfin, attacked Christian territories, but this time the chosen city was not Toledo but [[Uclés]].{{Sfn|Reilly|1992|p=97}}{{Sfn|Guichard|1989|p=528}} Alfonso VI was in [[Sahagún]], recently married, elderly and with an old wound that prevented him from riding. Álvar Fáñez, governor of the lands of the Banu Di-l-Nun, was the commander of the army. He was accompanied by [[Sancho Alfónsez]], the king's only son and heir.{{Sfn|Reilly|1992|p=97}}{{Sfn|Guichard|1989|p=528}} The armies clashed in the [[Battle of Uclés (1108)|Battle of Uclés]] on 29 May 1108 and the Christian troops suffered another defeat. The young Sancho Alfónsez, heir to the throne, was killed in battle. As a consequence, the ''reconquista'' came to a 30-year standstill, and the County of Portugal eventually became an independent kingdom.{{Sfn|Reilly|1992|p=97}}{{Sfn|Guichard|1989|p=528}} The military situation was also serious since the Almoravids almost immediately seized the entire defensive border of the Tagus valley from [[Aranjuez]] to [[Zorita de los Canes|Zorita]] and there were uprisings of the Muslim population in this region.{{Sfn|Reilly|1992|p=97}}

===Succession crisis===
Alfonso VI, already old, had to deal with the problem of his succession.{{Sfn|Reilly|1992|pp=95–96}} Berta had died without giving him an heir at the end of 1099; shortly after, Alfonso married Isabel who gave him two daughters, but no sons.{{Sfn|Reilly|1992|p=96}} To further complicate the situation, in March 1105 his grandson [[Alfonso VII of León|Alfonso Raimúndez]], son of Urraca and Raymond of Burgundy, was born,{{Sfn|Reilly|1992|p=96}} a possible contender to the throne in detriment to Sancho Alfónsez, the king's son with Zaida.{{Sfn|Reilly|1992|p=96}} Montenegro thinks that Alfonso VI legitimized Sancho probably coinciding with the meeting of a council in [[Carrión de los Condes]] in January 1103 because from that date onwards, Sancho began to confirm royal charters before his brothers-in-law Raymond and Henry of Burgundy.{{Sfn|Montenegro|2010|pp=377 and 383}} In May 1107, Alfonso imposed the recognition of Sancho as heir, despite the probable opposition of his daughters and sons-in-law,{{Sfn|Reilly|1992|p=96}} in the course of a ''Curia Regia'' held in León.{{Sfn|Montenegro|2010|pp=387}} The situation improved for the king with the death of Raymond of Burgundy in September and the agreement with Urraca so that she remained as sovereign Lady of Galicia,{{Sfn|Martínez Díez|2003|p=172}} except in the case of remarrying since, in that case, Galicia would pass to her son.{{Sfn|Reilly|1992|pp=96–97}}

The death of Sancho in the Battle of Uclés on 29 May 1108 left Alfonso VI without his only male heir. He then chose his eldest legitimate daughter Urraca as his successor, but decided to marry her to his rival and famous warrior King [[Alfonso the Battler|Alfonso I of Aragon and Navarre]] in the autumn of 1108.{{Sfn|Reilly|1992|p=97}} Although the marriage was celebrated at the end of the following year, it did not lead to the expected stability, but to a long civil war that lasted eight years.{{Sfn|Reilly|1992|p=98}}

===Death and burial===
Alfonso VI died in [[Toledo, Spain|Toledo]] on 1 July 1109.{{Sfn|Elorza|Vaquero|Castillo|Negro|1990|pp=54–55}} The king had come to the city to try to defend it from an imminent Almoravid attack.{{Sfn|Reilly|1992|p=98}} His body was taken to the locality of [[Sahagún]], and was buried in the Royal Monastery of San Benito, thus fulfilling the wishes of the monarch.{{Sfn|Elorza|Vaquero|Castillo|Negro|1990|pp=54–55}} The mortal remains of the king were deposited in a stone sepulchre, which was placed at the feet of the church of the Royal Monastery, until the reign of [[Sancho IV of Castile|Sancho IV]], who deemed it unseemly that his ancestor was buried at the foot of the temple and ordered the tomb to be moved inside and placed in the church's transept, near the tomb of Beatriz, Dowager Lady of Los Cameros and daughter of Infante [[Frederick of Castile]] who had been executed by orders of his brother, King [[Alfonso X of Castile|Alfonso X the Wise]] in 1277.{{Sfn|Arco y Garay|1954|pp=193–195}}

The sepulchre that contained the remains of the king, now having disappeared, was supported on alabaster lions, and was a large ark of white marble, eight feet long and four wide and tall, being covered by a smooth black lid. The tomb was usually covered by a silk tapestry, woven in [[Flanders]], bearing the image of the king crowned and armed, with the representation of the arms of Castile and León on the sides, and a crucifix at the head of the tomb.{{Sfn|Arco y Garay|1954|pp=193–195}}

The tomb that contained the remains of Alfonso VI was destroyed in 1810, during the fire at the Royal Monastery of San Benito. The mortal remains of the king and those of several of his wives were collected and preserved in the abbey chamber until 1821, when the monks were expelled, and were then deposited by the abbot Ramón Alegrías in a box, which was placed in the southern wall of the chapel of the Crucifix until January 1835, when the remains were collected again and placed in another box and taken to the archive where the remains of the wives of the sovereign were at that time. The purpose was to place all the royal remains in a new sanctuary that was being built at that time.{{Sfn|Arco y Garay|1954|pp=193–195}} However, when the Royal Monastery of San Benito was dissolved in 1835, the monks delivered the two boxes with the royal remains to a relative of one of them, who kept it hidden until 1902, when these were discovered by Rodrigo Fernández Núñez, a professor at the Institute of Zamora Rodrigo.{{Sfn|Arco y Garay|1954|pp=193–195}}

The mortal remains of Alfonso VI are now in the Monastery of the Benedictine nuns of Sahagún, at the foot of the temple, in a smooth stone ark and with a cover of modern marble, and in a nearby sepulchre, equally smooth, lie the remains of several of the king's wives.{{Sfn|Elorza|Vaquero|Castillo|Negro|1990|pp=54–55}}