The Crusade of Frederick II

I. The Boy of Apulia

Frederick II was born at Iesi in the March of Ancona on 26 December 1194, the son of the emperor Henry VI and of Constance, heiress of the Norman kingdom of Sicily. His mother, aged forty, is said to have given birth in a tent in the town square so that no one could doubt that the child was hers. His father died in 1197 and his mother in 1198, leaving him as a child king of Sicily under the guardianship of Pope Innocent III.

He grew up in Palermo, a city of Greek, Latin, Arabic and Jewish culture, in a kingdom whose Norman rulers had employed Muslim soldiers and Greek administrators and had patronised Arabic learning. Frederick learned several languages, possibly including Arabic, and developed a lifelong curiosity about nature, philosophy and science. He wrote a famous treatise on falconry, The Art of Hunting with Birds, based on his own observations, and he corresponded with Muslim and Jewish scholars on questions of philosophy and mathematics.

In 1212, with the support of Innocent III, he went to Germany to claim the imperial throne from Otto IV. After Otto's defeat at Bouvines in 1214, Frederick was crowned king of Germany at Aachen in July 1215, and on that occasion he took the cross.

II. The Vow and its Delays

Frederick's vow of 1215 made him the expected leader of the Fifth Crusade, but he did not go. He was occupied with securing his position in Germany and Sicily, and he was crowned emperor in Rome by Honorius III in November 1220, renewing his vow. The failure at Damietta in 1221 was blamed by many on his absence.

At San Germano in July 1225 he made an agreement with Honorius under which he promised to depart in August 1227 with 1,000 knights and to maintain them for two years, to provide 100,000 ounces of gold, and to transport 2,000 knights. If he failed, he would be excommunicated. Meanwhile, in November 1225, he married Isabella II, the fourteen-year-old heiress of the kingdom of Jerusalem, at Brindisi, and immediately took the title of king of Jerusalem, displacing his father-in-law, John of Brienne, who had expected to remain regent for life. Isabella died in 1228 after giving birth to a son, Conrad, who became the legal heir to the kingdom.

III. Gregory IX and the Excommunication

In March 1227 Honorius died and was succeeded by Gregory IX, a nephew of Innocent III and a determined defender of papal authority. Frederick assembled a large army at Brindisi in the summer of 1227, but an epidemic broke out in the crowded camp. Frederick sailed in September but fell ill, and after the death of the Landgrave Louis of Thuringia he put into Otranto to recover, sending the fleet on under Duke Henry of Limburg.

Gregory refused to accept the excuse. On 29 September 1227 he excommunicated Frederick for failing to fulfil his vow, and he renewed the sentence in more solemn terms in November, accusing the emperor of a long list of crimes against the church. The conflict was about more than the crusade. Frederick ruled both Germany and the kingdom of Sicily, surrounding the papal states, and the popes feared his power in Italy.

Frederick responded with an open letter to the princes of Europe, defending his conduct and accusing the papacy of greed and ambition. In June 1228, still excommunicate, he sailed for the east. Gregory regarded the departure of an excommunicated emperor on crusade as a scandal and forbade anyone to help him.

IV. Cyprus

Frederick reached Cyprus in July 1228. As emperor he claimed overlordship of the island, whose king had done homage to his father, Henry VI. The king of Cyprus, Henry I, was a child, and the regency was held by John of Ibelin, lord of Beirut, the most powerful baron of the Latin east. At a banquet in Limassol, Frederick surrounded the hall with soldiers and demanded that John surrender the regency and the city of Beirut. John refused, saying that he held Beirut as a fief of the kingdom of Jerusalem and would answer for it only before the High Court of the kingdom.

The confrontation began a long conflict between Frederick's representatives and the Ibelin family, known as the War of the Lombards, which divided the Latin east for over a decade. The barons of Outremer were jealous of their rights under the customs of the kingdom, and they resisted the attempts of the emperor to rule them as he ruled Sicily. The legal treatise of Philip of Novara, a supporter of the Ibelins, describes the conflict.

V. Arrival at Acre

Frederick landed at Acre in September 1228 with a small army. The troops who had gone ahead in 1227 had mostly gone home. He was received coldly by the clergy, who had been told of his excommunication, and the Templars and Hospitallers refused to serve under him, though they eventually agreed to march with him if orders were issued in the name of God and Christendom rather than the emperor. Only the Teutonic Knights, whose master Hermann of Salza was his close adviser, supported him fully.

Frederick's military strength was too small for a campaign of conquest. But he had a diplomatic advantage. Some years before, the sultan al-Kamil of Egypt had approached him, seeking an alliance against his brother al-Mu'azzam of Damascus, and offering Jerusalem in return. Frederick's envoy Thomas of Acerra and al-Kamil's envoy Fakhr al-Din ibn al-Shaikh had exchanged embassies. But al-Mu'azzam had died in November 1227, and al-Kamil no longer needed Frederick's help.

VI. The Negotiations

The negotiations that followed are among the most remarkable episodes of the crusades. Al-Kamil was encamped at Nablus, besieging Damascus, which was held by his nephew al-Nasir Dawud. Frederick moved his army to Jaffa and began rebuilding its fortifications, making a show of force. The two rulers never met, but their envoys travelled back and forth for months, and they exchanged gifts. Frederick sent al-Kamil questions on philosophy and mathematics, and the sultan sent him answers from his scholars, an elephant and other exotic animals.

Fakhr al-Din became Frederick's friend, and Arab sources report their conversations on philosophy and government. According to the Arabic historian Sibt ibn al-Jawzi, Frederick told Fakhr al-Din that he had no wish to take Jerusalem, but that his prestige in the west would be destroyed if he went home with nothing. Al-Kamil, for his part, faced criticism from Muslim opinion for negotiating the surrender of the holy city, but he needed peace with the Franks to complete his conquest of Damascus.

VII. The Treaty of Jaffa

The treaty was signed on 18 February 1229. Al-Kamil surrendered Jerusalem, Bethlehem and Nazareth to Frederick, together with a corridor of land linking Jerusalem to the coast at Jaffa, and parts of the territory around Sidon and Toron. The Muslims were to keep the Temple Mount, the Haram al-Sharif, with the Dome of the Rock and the al-Aqsa Mosque, which would remain under Muslim control with freedom of access for Muslim worshippers. Jerusalem was to remain unwalled, though this clause was disputed. A truce of ten years, five months and forty days was agreed.

The treaty achieved by negotiation what the Third and Fifth Crusades had failed to achieve by war. It returned Jerusalem to Christian rule for the first time since 1187 without a battle. But it was denounced on both sides. In the Muslim world, preachers in Damascus lamented the surrender of the holy city, and al-Kamil was condemned for betraying Islam. In the Christian world, the patriarch of Jerusalem, Gerold of Lausanne, placed the city under interdict and denounced the treaty, arguing that the Temple Mount should not have been left to the Muslims and that the city could not be defended.

VIII. The Crown in the Holy Sepulchre

Frederick entered Jerusalem on 17 March 1229. On the following day, a Sunday, he went to the Church of the Holy Sepulchre. No clergy would celebrate Mass for an excommunicate in a city under interdict. Frederick took the crown from the altar and placed it on his own head, or, according to some accounts, had Hermann of Salza place it there. Hermann read a manifesto in German and French, in which Frederick explained his actions and justified the treaty, blaming the pope for the difficulties he had faced.

The ceremony has been interpreted in many ways. Some historians have seen it as a self-coronation, an assertion of imperial authority independent of the church. Others think it was a crown-wearing, a ceremony in which a king who had already been crowned wore his crown on a solemn occasion. Either way, it was a striking demonstration that Frederick did not depend on the church for his authority.

IX. Frederick and the Haram

Frederick visited the Dome of the Rock and the al-Aqsa Mosque, guided by the qadi of Nablus, Shams al-Din. Arabic chroniclers recorded his visit with interest. He admired the buildings and asked questions about the inscriptions. According to one account, when he saw a Christian priest enter the al-Aqsa Mosque with a Gospel book, he struck him and threatened to kill any Frank who entered without permission. He is also said to have noticed that the muezzins had been told to keep silent out of respect for him, and to have asked them to give the call to prayer as usual.

The Arabic writers were divided in their view of him. Some admired his learning and his courtesy, while others noted his unimpressive appearance, short, red-haired and short-sighted, and remarked that if he had been a slave he would not have fetched two hundred dirhams. Some reported that he did not seem to be a believing Christian, and he was suspected in the west of being a sceptic or even a secret Muslim. His reputation as a free-thinker grew in later centuries.

X. The Return to Italy

Frederick could not stay long in the east. During his absence, Gregory IX had raised an army under the command of John of Brienne, Frederick's own father-in-law, and invaded the kingdom of Sicily. The papal troops wore the sign of the keys of St Peter and were promised crusade indulgences for fighting the emperor. This was the first time that a pope had used a crusade against a Christian ruler in the heart of Christendom on such a scale.

Frederick left Acre on 1 May 1229. His departure was humiliating, as the butchers of the city pelted him with offal as he went to his ship. He landed at Brindisi in June and quickly drove the papal army out of his kingdom. In July 1230 he made peace with Gregory at San Germano and Ceperano, and the excommunication was lifted. But the conflict between the emperor and the papacy was only interrupted.

XI. The War of the Lombards

In the east, Frederick left the kingdom under the rule of his representatives, notably his marshal Richard Filangieri, whose attempts to impose imperial authority provoked the barons. The Ibelins and their supporters, using the commune of Acre as their base, fought a long war against the imperialists, who held Tyre. In 1232 the Ibelins defeated the imperial forces in Cyprus at the battle of Agridi. In 1243 the barons took Tyre, and imperial power in the kingdom effectively came to an end.

The conflict revealed the weakness of the crusader states. Their nobility was divided, their kings absent, and their defence dependent on the military orders and the Italian commercial communities, which pursued their own interests. The site's page on the Crusader States and Military Orders describes this world.

XII. Jerusalem under the Treaty

Christian Jerusalem between 1229 and 1244 was a fragile possession. The walls had been destroyed by al-Mu'azzam in 1219, and Frederick's representatives did not rebuild them fully. The city was surrounded by Muslim territory, and the corridor to the coast was vulnerable. In 1229, shortly after Frederick's departure, Muslim villagers from the surrounding area attacked the city, and the Christian inhabitants took refuge in the Tower of David until help arrived from Acre.

The truce expired in 1239. In that year al-Nasir Dawud of Kerak occupied Jerusalem and destroyed the Tower of David. The city was returned to the Christians by a further treaty in 1241, negotiated by Richard of Cornwall, the brother of the English king, during the so-called Barons' Crusade. But in August 1244 the Khwarazmian Turks, displaced by the Mongols and allied with the sultan of Egypt, sacked Jerusalem and killed many of its Christian inhabitants. The city was not under Christian rule again until 1917.

XIII. The Battle of La Forbie

The loss of Jerusalem in 1244 was followed by a greater disaster. On 17 October 1244 the army of the crusader states, allied with the Ayyubid rulers of Damascus and Homs, was destroyed by the Egyptian army and the Khwarazmians at La Forbie, near Gaza. The Templars and Hospitallers lost almost all their knights in the battle, and the master of the Temple was killed. It was the worst defeat of the Latin states since Hattin. The news prompted Louis IX of France to take the cross, beginning the Crusade of Louis IX.

XIV. The Teutonic Knights

Frederick's crusade marked the rise of the Teutonic Order. Hermann of Salza, its master from 1209 to 1239, was Frederick's friend and adviser and acted as mediator between the emperor and the pope. The order received rich grants in the kingdom of Jerusalem, including the castle of Montfort, which became its headquarters in the east, and estates in Sicily and Germany.

At the same time Hermann saw an opportunity in the Baltic. By the Golden Bull of Rimini, traditionally dated 1226 though some historians argue it was issued about 1235 and backdated, Frederick granted the order the right to rule the lands of Prussia that it might conquer from the pagan Prussians. The order began its war in Prussia in 1230, and over the following decades it created a state that outlasted the crusader states in the east. The site's page on the Prussian Crusade describes this.

XV. The Crusade against Frederick

The conflict between Frederick and the papacy resumed in 1239, when Gregory IX excommunicated him again. In 1245 Pope Innocent IV, at the First Council of Lyons, declared Frederick deposed, and a crusade was preached against him in Germany and Italy. The papacy diverted funds collected for the Holy Land to the war against the emperor. When Louis IX was preparing his crusade, the pope's preoccupation with Frederick was a source of irritation in France.

Frederick died in December 1250. The papacy continued the war against his sons Conrad and Manfred and his grandson Conradin, and in 1266 Charles of Anjou, the brother of Louis IX, conquered the kingdom of Sicily with papal backing, again with crusading privileges. Conradin was beheaded in Naples in 1268, ending the Hohenstaufen dynasty. The crusade had become an instrument of papal politics in Italy, a development that many contemporaries condemned.

XVI. The Jewish Communities of Frederick's Realms

Frederick's attitude to Jews was shaped by both practical and intellectual interests. In 1236, when the Jews of Fulda were accused of killing Christian children to use their blood, he ordered an investigation by converts from Judaism, who were thought to know Jewish customs, and on their findings he issued a decree declaring the accusation false and forbidding it to be repeated. This was one of the earliest official refutations of the blood libel.

In 1236 he also declared the Jews of Germany to be servants of the imperial chamber, a status that gave them protection in return for taxes. In Sicily he employed Jewish scholars to translate Arabic and Hebrew works, including those of Maimonides. Jacob Anatoli, a son-in-law of the translator Samuel ibn Tibbon, worked at his court in Naples and translated Averroes into Hebrew. Michael Scot, the emperor's astrologer, worked with Jewish collaborators on translations of Aristotle and his commentators.

XVII. Peace by Negotiation

Frederick's crusade challenged the ideology of the crusade. He recovered Jerusalem without bloodshed, through diplomacy and an understanding with a Muslim ruler, at a time when he was excommunicated and his lands were being attacked by the pope. His treaty recognised Muslim rights in the holy city. To his critics it was a betrayal, an agreement with the enemies of Christ. To later admirers it was an example of reason and tolerance.

The episode raises questions about the use of force in religion. Jesus taught his disciples to love their enemies and pray for those persecuting them (Matthew 5:43-45), and Paul urged that, if possible, as far as it depends on you, be peaceable with all men (Romans 12:17-18). Frederick was hardly a model of such conduct, since he fought ruthless wars in Italy. But his treaty shows that even within the crusade movement, there were alternatives to violence.

XVIII. The Sacred Places

The dispute over Jerusalem in 1229 reveals how much the crusade depended on the idea that certain places were holy and must be controlled by Christians. The Church of the Holy Sepulchre, the Temple Mount and the other sacred sites were the focus of devotion and conflict. Yet Jesus told the Samaritan woman that the hour was coming when people would worship the Father neither on that mountain nor in Jerusalem, but in spirit and truth (John 4:21-24). Stephen, before his death, reminded the Sanhedrin that the Most High does not dwell in houses made with hands (Acts 7:48-50).

The Greek Scriptures do not teach that Christians must possess Jerusalem or any other place. The struggle for the sacred sites, which cost so many lives over two centuries, rested on a view of holiness that the early Christians did not hold. Paul wrote of the Jerusalem above as free and as the mother of Christians (Galatians 4:25-26), contrasting it with the earthly city.

XIX. Sources

The crusade of Frederick II is described in the western sources from very different perspectives. The imperial side is represented by Frederick's own manifesto and letters, and by the chronicle of Richard of San Germano. The papal and clerical side is represented by the letters of Gregory IX and of Patriarch Gerold, which denounce the emperor in the strongest terms. The barons' view is given by Philip of Novara and the continuations of William of Tyre, which are hostile to Frederick and to his officials.

The Arabic sources are valuable. Sibt ibn al-Jawzi, a preacher in Damascus, described the grief in the city at the news of the treaty and preached a sermon lamenting the loss of Jerusalem. Ibn Wasil, a historian who later served as an envoy to Frederick's son Manfred, described the negotiations and the emperor's character. The Arabic biographer Ibn Khallikan recorded the friendship of Fakhr al-Din and the emperor.

XX. Assessment

Frederick's crusade was the most successful in terms of territory recovered since the First, and it achieved its goal with almost no fighting. Yet it was carried out by an excommunicated emperor against the opposition of the pope, the patriarch and the military orders of the Temple and the Hospital. Its gains proved temporary because the crusader states lacked the strength to hold Jerusalem and because the divisions among the Christians prevented a common policy.

It also showed how far the crusade had become entangled with papal politics in Europe. The papacy that had launched the crusades now used crusading against a Christian emperor who had just recovered Jerusalem. The spectacle disillusioned many and contributed to the decline of the crusading ideal in the later thirteenth century.

XXI. Al-Kamil

Al-Malik al-Kamil Nasir al-Din Muhammad was the son of al-Adil and nephew of Saladin. He governed Egypt from about 1200 as his father's deputy and became sultan on his father's death in 1218, in the middle of the siege of Damietta. He defended Egypt successfully against the Fifth Crusade and treated the defeated crusaders generously. He was an able administrator who improved the irrigation of Egypt, supported scholarship and built a madrasa in Cairo for the study of the traditions of the Prophet.

Al-Kamil's policy towards the Franks was pragmatic. He regarded Jerusalem as less important than the security of Egypt and the unity of the Ayyubid lands under his leadership. He had offered the city twice during the Fifth Crusade, and he was willing to trade it again to secure Frederick's neutrality while he dealt with his relatives in Syria. After the treaty he took Damascus in 1229 and gave it to his brother al-Ashraf, and he spent his remaining years trying to hold the Ayyubid family together. He died in Damascus in March 1238, having taken the city again shortly before his death. His death was followed by civil war among his heirs.

XXII. The Muslim Reaction

The news of the treaty was received with grief in much of the Muslim world. In Damascus al-Nasir Dawud, who was at war with his uncle al-Kamil, used the treaty to rally opinion against him. He asked the preacher Sibt ibn al-Jawzi to preach in the Great Mosque about the loss of Jerusalem, and Sibt described the scene: the people wept and lamented, and there was no day like it. The poets wrote laments for the holy city.

The scholars of Egypt were more reticent, but some criticised the sultan for surrendering the city in which the Prophet had begun his night journey to heaven. Al-Kamil's defenders argued that the treaty protected the Haram, that Jerusalem without walls could be recovered at any time, and that peace with the Franks was necessary. The reaction showed that by the thirteenth century Jerusalem had become as important to Muslim religious feeling as it was to Christians, partly as a result of the propaganda of jihad that had developed in response to the crusades.

XXIII. Hermann of Salza

Hermann of Salza came from a family of Thuringian ministerials and became master of the Teutonic Order in 1209 or 1210. When he took office the order was small and poor, with only a few knights. By his death in 1239 it was one of the great powers of Christendom, with houses throughout the empire, estates in Sicily, Greece and the Holy Land, and a growing state in Prussia.

Hermann's success rested on his relationship with both the emperor and the papacy. He was trusted by Frederick, who consulted him on all major questions, and he was respected by Honorius III and Gregory IX, who used him as a mediator. He accompanied Frederick to the east and supported the treaty, and he negotiated the peace of San Germano in 1230. He was also one of the few figures who sought to reconcile the two powers whose conflict damaged the crusade. He died at Salerno in March 1239, on the day that Gregory IX excommunicated Frederick for the second time.

XXIV. Kingship in Absence

The kingdom of Jerusalem had never been ruled by an absent king before Frederick. The barons of the kingdom, who had developed an elaborate system of law based on the High Court and the customs written down in the Assizes of Jerusalem, believed that the king ruled with their counsel and according to their customs. Frederick, who ruled Sicily through a centralised bureaucracy, regarded them as subjects to be commanded.

The legal theorists of the kingdom, such as John of Ibelin, count of Jaffa, and Philip of Novara, developed sophisticated arguments for the rights of the barons, claiming that the king was bound by the law and that the vassals could resist him if he broke it. When Frederick's son Conrad came of age in 1243, the barons declared that since he had not come to the kingdom to receive their homage, they would govern through a regent from the royal family. The kingdom was ruled in this way for the rest of its existence, with absent kings and baronial regents.

XXV. Frederick and the Papacy

The quarrel between Frederick and the popes was the culmination of the long conflict between empire and papacy that had begun with the investiture controversy of the eleventh century. The popes claimed supreme authority in Christendom, including the right to depose rulers. Frederick claimed that the emperor derived his authority directly from God and owed the pope only spiritual reverence.

Both sides used extreme language. Gregory IX called Frederick the beast from the sea described in Revelation, full of names of blasphemy. Frederick's chancery replied by calling the pope the great dragon and the Antichrist. The apocalyptic rhetoric shows how the language of the Scriptures was turned to political use. Jesus taught his followers to pay back Caesar's things to Caesar but God's things to God (Mark 12:17), a principle that neither popes nor emperors observed in their struggle for supremacy.

XXVI. The Barons' Crusade

The truce of 1229 expired in 1239, and a new crusade set out to defend the kingdom. It was led first by Thibaut IV, count of Champagne and king of Navarre, a famous poet, and then by Richard, earl of Cornwall. Thibaut's army was defeated near Gaza in November 1239, but he negotiated an agreement with the ruler of Damascus that returned some territory. Richard of Cornwall, arriving in 1240, negotiated with the sultan of Egypt, al-Salih Ayyub, who confirmed the return of Jerusalem and other lands.

By 1241 the kingdom had recovered more territory than at any time since 1187, including Galilee, Jerusalem and the castles of Beaufort and Safed. Like Frederick, the leaders of the Barons' Crusade gained these lands by diplomacy, exploiting the divisions among the Ayyubid princes. But the gains were lost three years later, when the Franks allied with Damascus against Egypt and were defeated at La Forbie.

XXVII. Frederick's Reputation

Frederick fascinated his contemporaries and has fascinated historians ever since. The English chronicler Matthew Paris called him the wonder of the world. To the papacy he was a heretic and a tyrant. Dante placed him in the circle of the heretics in the Inferno, among the Epicureans who denied the immortality of the soul. Legends grew up that he was not dead but sleeping, and would return to reform the church.

In the nineteenth and twentieth centuries he was seen as the first modern ruler, a rationalist and sceptic who anticipated the Renaissance. Ernst Kantorowicz's biography of 1927 presented him as a heroic figure of German destiny. Modern historians such as David Abulafia have presented a more sober picture, of a conventional medieval ruler, concerned to defend his rights and conventional in his piety, whose originality has been exaggerated. His crusade, nevertheless, remains a striking example of how a crusade could succeed by negotiation rather than war.

XXVIII. Lucera

Frederick's treatment of the Muslims of Sicily stands in contrast to his diplomacy in the east. The Muslims of western Sicily, who had lived under Norman rule, rebelled in the years of his minority and held out in the mountains. Between about 1220 and 1246 Frederick defeated them and deported some 15,000 to 20,000 to Lucera in Apulia, where they were settled as a self-governing community under royal protection. They were allowed to practise their religion, and they provided Frederick with loyal soldiers and craftsmen, including his personal guard.

The papacy protested at the existence of a Muslim colony in the heart of Christian Italy, and Frederick's use of Muslim troops against papal forces was one of the charges against him. The colony survived his death but was destroyed in 1300 by Charles II of Anjou, who sold its inhabitants into slavery. Lucera shows both the pragmatism of Frederick's rule and its harshness, since the deportation uprooted a whole population from its homeland.

XXIX. A Note on the Sources for the Crown-wearing

No eyewitness account describes exactly how the crown was placed on Frederick's head in March 1229. The emperor's own manifesto, the hostile letter of Patriarch Gerold and the later chronicles differ in detail, and the interpretations above should be read with this uncertainty in mind.

XXX. Chronology

On 26 December 1194 Frederick was born. In July 1215 he was crowned at Aachen and took the cross. In November 1220 he was crowned emperor. In July 1225 the agreement of San Germano was made. In November 1225 he married Isabella II. In 1226, by its traditional dating, which is disputed, the Golden Bull of Rimini was issued. In March 1227 Gregory IX became pope, and in November 1227 al-Mu'azzam died. On 29 September 1227 Frederick was excommunicated. In June 1228 he sailed, and in September 1228 he reached Acre.

On 18 February 1229 the Treaty of Jaffa was signed. On 17 March 1229 Frederick entered Jerusalem, and on 18 March he wore the crown in the Holy Sepulchre. On 1 May 1229 he left Acre. In July 1230 the peace of San Germano was made. In 1239 the truce expired and Frederick was excommunicated again. In 1241 Jerusalem was restored by treaty. In August 1244 the Khwarazmians sacked Jerusalem, and on 17 October 1244 the Latin army was destroyed at La Forbie. In 1245 Frederick was deposed at Lyons, and in December 1250 he died.

XXXI. Bibliography

The following studies, editions and reference works underlie this account.