Editing Crusading movement (section)

==Background==

The [[crusades]] are commonly defined as [[religious war]]s waged for the [[holy city]] of Jerusalem in [[Palestine (region)|Palestine]] by western European warriors in the [[Middle Ages]].{{sfn|Hornby|2005|p=370}}{{sfn|Nicholson|2004|p=xlviii}} However, their [[Theater (warfare)|theaters of war]], timeframe and motivation are flexible in academic studies.{{sfn|Jotischky|2017|pp=10–11}}{{sfn|Nicholson|2004|pp=xl–xli, xlviii}} The crusading movement heavily influenced medieval societies with its own institutions and ideas in both [[Catholic Europe]] and the neighbouring regions.{{sfn|Murray|2006|p=xxxi}}{{sfn|Lloyd|2002|p=65}}

===Classical just war theories===

[[File:BritLibRoyal5DVIIFolio067r.JPG|right|thumb|alt=A page from a centuries-old hand-written codex with a large initial letter in the text|A page from an early-12th-century [[manuscript]] of ''[[The City of God]]'' by [[Augustine]]]]

In [[classical antiquity]], [[Greek philosopher]]s and [[Roman law]]yers developed [[just war theory|just war theories]] that would influence crusading [[Christian theology|theology]]. The philosopher [[Aristotle]] emphasised the importance of a war's just end, stating that "war must be for the sake of peace". According to Roman lawyers, a {{Transliteration|la|[[casus belli]]}} (or just cause) was needed to wage a war, and only a [[Legitimacy (political)|legitimate]] authority could declare it. They cited the defence of the homeland, the restitution of lost property, and punishment as just causes.{{sfn|Tyerman|2019|pp=13–14}} The [[Bible]]—the Christians' most sacred book—contains contradictory statements [[Christianity and violence|about violence]],{{refn|group=note|The [[Old Testament]] portrays the [[Israelites]]' struggles against their enemies as [[God in Judaism|godly]] sanctioned wars but also mentions that God's [[Thou shalt not kill|Fifth Commandment]] prohibits [[homicide]]; in the [[New Testament]], [[Jesus]] says that "[[Live by the sword, die by the sword|all who take the sword will perish by the sword]]", but also states that he has "[[Matthew 10:34|not come to bring peace, but a sword]]".{{sfn|Asbridge|2012|pp=14–15}}}}{{sfn|Jaspert|2006|p=14}} but the [[Christianisation of the Roman Empire|Christianisation of]] the militant [[Roman Empire]] entailed the development of Christian theories of just war from the {{nowrap|4th century}}. The ex-official turned bishop [[Ambrose]] was the first to teach that the enemies of the Christian church and state were one and the same.{{sfn|Tyerman|2019|p=14}}{{sfn|Madden|2013|p=2}}

The empire was divided into two parts in 395.{{sfn|Lock|2006|p=358}} Fifteen years later, the city of Rome was [[Sack of Rome (410)|sacked by]] the wandering [[Visigoths]], prompting Ambrose's pupil [[Augustine]] to complete a monumental historical study, entitled ''[[The City of God]]''.{{sfn|Backman|2022|pp=56–59}} In it, he stated that the biblical "[[Thou shalt not kill|commandment forbidding killing]] was not broken by those who have waged war on the authority of [[God in Christianity|God]]".{{sfn|Tyerman|2019|p=15}} In Augustine's concept, a just war must be declared by a legitimate authority for a legitimate reason after peaceful resolutions proved impossible, and must be waged with good intent without the excess use of violence. For him, legitimate reasons for warring include defence, the enforcement of a judicial decision, and the restoration of stolen goods.{{sfn|Tyerman|2019|p=14}}{{sfn|Jaspert|2006|p=15}} Augustine's scattered statements about warring were nearly forgotten after [[Fall of the Western Roman Empire|the fall of]] the [[Western Roman Empire]] in 476.{{sfn|Tyerman|2019|p=14}}{{sfn|Jaspert|2006|pp=14–15}}

===Tripartite world===

[[Barbarian kingdoms|New Christian kingdoms]], dominated mainly by [[Germanic peoples|Germanic]] warlords, emerged in the western empire's ruins. In the new aristocracy's eyes, comradeship and warring were integral elements of life, and [[Western Christianity|Western Christian]] clerics had to praise their often violent acts to gain their patronage.{{sfn|Tyerman|2007|pp=35–36}} However, churchmen regarded homicide as a [[Catholic hamartiology|sin]], and prescribed acts of [[penance]] (such as [[Fasting and abstinence in the Catholic Church|fasting]]){{sfn|Thomson|1998|pp=69–70}} for those who had killed someone in a battle and requested [[absolution]].{{sfn|Jaspert|2006|pp=14, 30–31}}

The [[Eastern Roman Empire]] (now also known as the Byzantine Empire) survived but much of its territory, including Palestine, was [[Early Muslim conquests|conquered by]] a new power, the [[Rashidun Caliphate|Islamic Caliphate]] by the middle of the {{nowrap|7th century}}.{{sfn|Backman|2022|pp=126, 141–143}}{{sfn|Lock|2006|p=4}} Several [[Āyah|verses]] of the [[Quran]]—the holiest text of [[Islam]]{{sfn|Backman|2022|pp=137–138}}—refer to the {{Transliteration|ar|[[jihad]]}}, the struggle of the faithful, or [[Muslims]], for the spread of their faith.{{refn|group=note|Both the {{Transliteration|ar|jihad}} and the crusades are holy wars, but nothing proves that they were connected in any way. The historian Paul M. Cobb attributes their similar features to "their common roots in a universal [[monotheism]] whose God is [[Thou shalt have no other gods before me|a jealous god]]".{{sfn|Cobb|2016|p=29}}}}{{sfn|Hillenbrand|2018|pp=89–91}}{{sfn|Jaspert|2006|p=75}} The Islamic expansion reached Europe with the [[Muslim conquest of the Iberian Peninsula|conquest of]] much of the [[Iberian Peninsula]] in the early {{nowrap|8th century}}.{{sfn|Backman|2022|p=144}}{{sfn|Lock|2006|p=6}} Christians living under Muslim rule were not required to convert to Islam but had to pay a special tax, the {{Transliteration|ar|[[jizya]]}}.{{sfn|Cobb|2016|p=30}} With the consolidation of the Muslim conquests, three easily distinguishable civilisations emerged in former Roman lands: the turbulent Western Europe, a reduced Byzantine state, and the offensive Islamic world.{{sfn|Backman|2022|pp=144–146}}

===Holy wars and piety===

The Christians' resistance against Muslim invasions led to the formation of a kingdom, [[Kingdom of Asturias|Asturias]] in northwestern Iberia. In a century, the resistance turned into a war of expansion, regarded by the natives as a godly-sanctioned fight for their lost lands. Europe was frequently invaded by non-Christian forces during the {{nowrap|9th century}} which revived the idea of holy wars.{{sfn|Jaspert|2006|p=15}} Already in 846, [[Pope Leo IV]] promised [[Salvation in Christianity|salvation]] on God's behalf to those who died for the defence of the [[Patrimony of Saint Peter]] (the papal domains in Central Italy).{{sfn|Tyerman|2007|p=38}}{{sfn|Bysted|2014|pp=53–54}} The nearly permanent warfare brought about the formation of a new warrior class, mentioned as {{Transliteration|la|milites}} in contemporary sources. They were mounted warriors trained for the use of special weapons, such as a heavy lance.{{sfn|Jaspert|2006|p=16}}{{sfn|Bull|2002|p=24}} Church leaders initiated the [[Peace of God]] movement to reduce violence, punishing those who broke the Peace with [[Excommunication in the Catholic Church|excommunication]].{{sfn|Backman|2022|pp=213–214}}{{sfn|Jaspert|2006|pp=17–18}} The movement, quite oddly, contributed to the militarisation of the Church because church leaders often had to raise armies to effectively defend the Peace.{{sfn|Morris|2001|p=144}}

[[File:Rotunda, Adomanan de locis santis.jpg|right|thumb|alt=A page from a manuscript depicting the plan of a church with lines and a series of five concentring rings|Plan of the [[Church of the Holy Sepulchre]] in an early-9th-century [[manuscript]] of {{Transliteration|la|[[De locis sanctis]]}} ('About Sacred Places'), a work by the Irish monk [[Adomnán]]]]

In the lack of central authority, regional strongmen took control of the local [[Parish (Catholic Church)|parishes]] and [[abbey]]s. They appointed their own, often unworthy, candidates to church offices, although believers worried that irregularly appointed priests could not administer valid [[Sacraments of the Catholic Church|sacraments]].{{sfn|Backman|2022|pp=214–215}}{{sfn|Jaspert|2006|p=25}} Laypeople's anxiety over afterlife punishments intensified.{{sfn|Thomson|1998|pp=69–70}}{{sfn|Jaspert|2006|pp=30–31}} Sinners were expected to [[Confession (religion)|confess their sins]] and give a proper satisfaction (mainly in the form of acts of penance) before they were reconciled with the Church. The overall performance of penances proved difficult, which paved the way, {{circa|1030}}, for priestly grants of [[indulgence]]s—the commutation of burdensome penances into pious works, such as almsgiving to a church, or a [[Christian pilgrimage|pilgrimage]] to a [[shrine]].{{sfn|Mayer|2009|pp=25–27}}{{sfn|Bysted|2014|p=20, 96}} Penitential pilgrimages to Palestine—the venue of the [[Ministry of Jesus|ministry of]] Jesus Christ{{sfn|Cobb|2016|pp=33–34}}—were especially esteemed.{{sfn|Jaspert|2006|pp=21–22}} The [[Church of the Holy Sepulchre]] in Jerusalem, identified as the site of Jesus's [[Crucifixion of Jesus|crucifixion]] and [[Resurrection of Jesus|resurrection]], was the most popular Palestinian shrine.{{sfn|Tyerman|2019|pp=xxiii–xxv}}{{sfn|Jotischky|2017|pp=34–36}}

===Church reforms===

{{Further|Cluniac Reform|Gregorian Reform|History of the papacy (1048–1257)}}

The general fear of [[damnation]] induced church reform movements, initially under the leadership of prosperous [[Christian monasticism|monasteries]]. [[Cluny Abbey]] set an important precedent because its 910 foundation charter guaranteed the monks' right to [[Canonical election|freely elect]] their [[abbot]]. The [[Cluniac Reform]] quickly spread, mainly with the support of aristocrats who highly esteemed the monks' [[Intercession|prayers for their souls]].{{sfn|Thomson|1998|pp=33–35}}{{sfn|Jaspert|2006|pp=27–28}} The Cluniac houses were only subject to papal authority.{{sfn|Jaspert|2006|p=27}}{{sfn|Latham|2011|p=231}}

The popes, who were regarded as the successors of [[Saint Peter]] (one of Jesus's [[Twelve Apostles]]), claimed [[papal primacy|primacy]] over the entire Church, referring to Jesus's [[Confession of Peter#Selection of Peter|words of praise]] about Peter.{{sfn|Thomson|1998|p=39}} In reality, Roman noble families [[Tusculan Papacy|controlled]] the papacy until the [[Holy Roman Emperor]] [[Henry III, Holy Roman Emperor|Henry III]] conquered the city in 1053. He supported reformist clerics to implement their ideas about the "[[Libertas ecclesiae|liberty of the church]]". This so-called [[Gregorian Reform]] led to a ban on [[simony]] (the sale of church offices), and established the exclusive right of high-ranking clerics known as [[Cardinal (Catholic Church)|cardinals]] to [[papal elections|elect the popes]].{{sfn|Thomson|1998|pp=82–85}}{{sfn|Jotischky|2017|p=25}} Andrew Latham, an expert in [[international relations]], argues that "the (re)constitution of the fundamental identity" of the Western Church under the reformist popes "entailed the emergence of new core interests that placed the Church in a structurally antagonistic relationship with a range of social forces within and beyond Christendom".{{sfn|Latham|2011|p=240}} By this time, differences in theology and customs between the western and eastern branches of [[Chalcedonian Christianity|mainstream Christianity]] had become evident.{{refn|group=note|The [[filioque|unilateral modification]] of the [[Nicaean Creed]] by western clerics, and the use of [[Baker's yeast|leavened]] or [[Unleavened bread|unleavened]] bread during the [[Eucharist]] (a central element of Christian liturgy) were the most evident differences between the two Christian communities.{{sfn|Jaspert|2006|p=4}}}} The conflicts led to mutual excommunications in 1054, and eventually the separation of the western [[Roman Catholic Church|Roman Catholic]] and the eastern [[Greek Orthodox Church|Orthodox Churches]]. This [[East–West Schism]], however, did not abolish [[Full communion|communion]] between them.{{sfn|Jaspert|2006|p=4}}{{sfn|Jotischky|2017|pp=28–29}}

The establishment of new monastic orders (such as the [[Carthusians]] and [[Cistercians]]) and the spread of the ''[[Rule of Saint Augustine]]'' among secular clergy indicate a spiritual revival towards the end of the {{nowrap|11th century}}. [[Christocentrism]], a new form of [[spirituality]] focusing on Christ's life, became an important characteristic of religious life, inspiring a movement of wandering preachers who often ignored the bishops' authority.{{sfn|Jaspert|2006|p=29}}