Albigensian Crusade in the context of "Simon de Montfort, 5th Earl of Leicester"

Louis IX (25 April 1214 – 25 August 1270), also known as Saint Louis, was King of France from 1226 until his death in 1270. He is widely recognized as the most distinguished of the Direct Capetians. Following the death of his father, Louis VIII, he was crowned in Reims at the age of 12. His mother, Blanche of Castile, effectively ruled the kingdom as regent until he came of age, and continued to serve as his trusted adviser until her death. During his formative years, Blanche successfully confronted rebellious vassals and championed the Capetian cause in the Albigensian Crusade, which had been ongoing for the past two decades.

As an adult, Louis IX grappled with persistent conflicts involving some of the most influential nobles in his kingdom, including Hugh X of Lusignan and Peter I of Brittany. Concurrently, England's Henry III sought to reclaim the Angevin continental holdings, only to be decisively defeated at the Battle of Taillebourg. Louis expanded his territory by annexing several provinces, including parts of Aquitaine, Maine, and Provence. Keeping a promise he made while praying for recovery from a grave illness, Louis led the ill-fated Seventh and Eighth Crusades against the Muslim dynasties that controlled North Africa, Egypt, and the Holy Land. He was captured and ransomed during the Seventh Crusade, and later succumbed to dysentery during the Eighth Crusade. His son, Philip III, succeeded him.

Philip II (21 August 1165 – 14 July 1223), also known as Philip Augustus (French: Philippe Auguste), was King of France from 1180 to 1223. His predecessors had been known as kings of the Franks (Latin: rex Francorum), but from 1190 onward, Philip became the first French monarch to style himself "King of France" (rex Francie). The son of King Louis VII and his third wife, Adela of Champagne, he was originally nicknamed 'God-given' (Dieudonné) because he was a first son and born late in his father's life. Philip was given the epithet "Augustus" by the chronicler Rigord for having extended the crown lands of France so remarkably.

After decades of conflicts with the House of Plantagenet, Philip succeeded in putting an end to the Angevin Empire by defeating a coalition of his rivals at the Battle of Bouvines in 1214. This victory would have a lasting impact on western European politics: the authority of the French king became unchallenged, while John, King of England, was forced by his barons to assent to Magna Carta and deal with a rebellion against him aided by Philip's son Louis, the First Barons' War. The military actions surrounding the Albigensian Crusade helped prepare the expansion of France southward. Philip did not participate directly in these actions, but he allowed his vassals and knights to help carry them out.

In the history of the Catholic Church, a crusade indulgence was any indulgence—remission from the penalties imposed by penance—granted to a person who participated in an ecclesiastically sanctioned crusade. It had its origins in the Council of Clermont that closed on 27 November 1095. According to Lambert of Arras, who was present, the council decreed that, "Whoever for devotion alone, not to gain honour or money, goes to Jerusalem to liberate the Church of God can substitute this journey for all penance." This marked the start of the First Crusade. Later popes and councils often invoked "the same remission as instituted by Pope Urban at the council at Clermont." The connection to the liberation of Jerusalem was later weakened and the same or similar indulgence offered to participants in the Northern Crusades and the Albigensian Crusade.

Septimania is a historical region in modern-day southern France. It referred to the western part of the Roman province of Gallia Narbonensis that passed to the control of the Visigoths in 462, when Septimania was ceded to their king, Theodoric II. During the Early Middle Ages, the region was variously known as Gallia Narbonensis, Gallia, or Narbonensis. The territory of Septimania roughly corresponds with the modern French former administrative region of Languedoc-Roussillon that merged into the new administrative region of Occitanie. In the Visigothic Kingdom, which became centred on Toledo by the end of the reign of Leovigild, Septimania was both an administrative province of the central royal government and an ecclesiastical province whose metropolitan was the Archbishop of Narbonne. Originally, the Goths may have maintained their hold on the Albigeois, but if so it was conquered by the time of Chilperic I. There is archaeological evidence that some enclaves of Visigothic population remained in Frankish Gaul, near the Septimanian border, after 507.

The region of Septimania was invaded by the Andalusian Muslims in 719, renamed as Arbūnah and turned into a military base for future operations by the Andalusian military commanders. It passed briefly to the Emirate of Córdoba, which had been expanding from the south during the same century, before its subsequent conquest by the Christian Franks in 759, who by the end of the 9th century renamed it as Gothia or the Gothic March (Marca Gothica). Eventually, the Christian Franks chased the Muslim Arabs and Berbers away from Septimania and conquered Narbonne in 759, and the Carolingian king Pepin the Short came up reinforced. Septimania became a march of the Carolingian Empire and then West Francia down to the 13th century, though it was culturally and politically autonomous from the northern France-based central royal government. The region was under the influence of the people from the count territories of Toulouse, Provence, and ancient County of Barcelona. It was part of the wider cultural and linguistic region comprising the southern third of France known as Occitania. This area was finally brought under effective control of the French kings in the early 13th century as a result of the Albigensian Crusade, after which it was assigned governors. From the end of the thirteenth century Septimania evolved into the royal province of Languedoc.

Louis VIII (5 September 1187 – 8 November 1226), nicknamed The Lion (French: Le Lion), was King of France from 1223 to 1226. As a prince, he invaded England on 21 May 1216 and was excommunicated by a papal legate on 29 May 1216. On 2 June 1216, Louis was proclaimed "King of England" by rebellious barons in London, though never crowned. With the assistance of allies in England and Scotland he gained control of approximately one third of the English kingdom and part of Southern Wales. He was eventually defeated by English loyalists and those barons who swapped sides following the death of King John. After the Treaty of Lambeth, he was paid 10,000 marks, pledged never to invade England again, and was absolved of his excommunication.

As prince and fulfilling the crusading vow of his father, Philip II, Louis led forces during the Albigensian Crusade in support of Simon de Montfort the Elder, from 1219 to 1223, and as king, from January 1226 to September 1226. Crowned king in 1223, Louis's ordinance against Jewish usury, a reversal of his father's policies, led to the establishment of Lombard moneylenders in Paris.

The count of Toulouse (Occitan: comte de Tolosa, French: comte de Toulouse) was the ruler of Toulouse during the 8th to 13th centuries. Originating as vassals of the Frankish kings, the hereditary counts ruled the city of Toulouse and its surrounding county from the late 9th century until 1270. The counts and other family members were also at various times counts of Quercy, Rouergue, Albi, and Nîmes, and sometimes margraves (military defenders of the Holy Roman Empire) of Septimania and Provence. Count Raymond IV founded the Crusader state of Tripoli, and his descendants were also counts there.They reached the zenith of their power during the 11th and 12th centuries, but after the Albigensian Crusade the county fell to the kingdom of France, nominally in 1229 and de facto in 1271.

Later the title was revived for Louis Alexandre, Count of Toulouse, a bastard of Louis XIV (1678–1737).