Sixth Crusade (1228-1229): Frederick II Regains Jerusalem

The Sixth Crusade (1228–1229) was the expedition of the Holy Roman Emperor Frederick II to the Holy Land, during which he recovered Jerusalem without fighting a battle. By the Treaty of Jaffa, agreed in February 1229 with the Ayyubid sultan al-Kamil, Jerusalem returned to Christian rule for the first time since 1187. The crusade was unusual in every way: its leader had been excommunicated by the pope, and it succeeded through diplomacy rather than war.

Background

Frederick II, King of Sicily and Holy Roman Emperor, took the cross in 1215. His failure to join the Fifth Crusade was widely blamed for its defeat in Egypt in 1221. In 1225 he married Isabella II, heiress to the Kingdom of Jerusalem, and claimed the title of king.

Frederick sailed in 1227, but an epidemic struck his army and he fell ill, so he turned back. Pope Gregory IX, already in conflict with him over Italy, excommunicated him on 29 September 1227. Isabella died in late April or early May 1228, days after giving birth to their son Conrad, which weakened Frederick’s legal claim to the kingdom.

The crusade

Frederick sailed again in June 1228, while still excommunicated, stopped in Cyprus and reached Acre in September. His army was small, and many clergy and the military orders of the Templars and Hospitallers were reluctant to cooperate with an excommunicate. The Teutonic Knights under their master Hermann of Salza remained loyal to him.

On the Muslim side, the situation favoured negotiation. Sultan al-Kamil of Egypt had earlier sought Frederick’s help against his brother al-Mu’azzam of Damascus. Al-Mu’azzam had died in November 1227, and al-Kamil now wanted to take Damascus from his nephew al-Nasir Dawud. A war with the crusaders would have been a costly distraction.

Frederick, who knew Arabic culture well from Sicily, exchanged envoys and gifts with al-Kamil over several months, while marching to Jaffa to show his forces. On 18 February 1229 the two rulers agreed the Treaty of Jaffa.

The Treaty of Jaffa

The treaty gave Jerusalem, Bethlehem, Nazareth and a strip of land linking Jerusalem to the coast to the Franks. The truce was to last ten years, five months and forty days. Muslims kept the Temple Mount, known to them as the Haram al-Sharif, with the Dome of the Rock and al-Aqsa Mosque, and retained freedom of worship there. Jerusalem’s walls, which had been pulled down in 1219, were not to be rebuilt, though historians debate exactly what the treaty allowed.

Frederick entered Jerusalem on 17 March 1229. The next day he wore the crown of Jerusalem in the Church of the Holy Sepulchre, without a religious coronation. The Patriarch of Jerusalem, Gerald of Lausanne, then placed the city under an interdict, a ban on church services.

The treaty did not end the conflicts within the Frankish states. Frederick’s officials soon quarrelled with the local nobility, led by the Ibelin family, over who should govern the kingdom and Cyprus, a struggle known as the War of the Lombards that lasted until the 1240s.

Reaction and departure

The agreement angered many on both sides. Some Muslims in Damascus, including the preacher Sibt ibn al-Jawzi, condemned the surrender of Jerusalem. Many Franks resented a treaty that left the city hard to defend, and the church saw it as a deal made by an excommunicated ruler with the enemy.

Frederick also faced trouble at home, where papal troops had invaded his Kingdom of Sicily. He left Acre on 1 May 1229, reportedly pelted with offal by hostile townspeople, and drove the papal forces back. Peace with the pope came with the Treaty of San Germano in 1230, when his excommunication was lifted.

Key people

Frederick II (1194–1250), King of Sicily and Holy Roman Emperor, was one of the most remarkable rulers of the Middle Ages, curious about science, philosophy and the Islamic world, and nicknamed by contemporaries the “wonder of the world”. Al-Kamil (c. 1177–1238), sultan of Egypt, was a pragmatic ruler who had already offered Jerusalem to the crusaders at Damietta in 1219. Hermann of Salza, master of the Teutonic Knights, acted as Frederick’s chief adviser and mediator with the papacy. Pope Gregory IX saw the emperor’s power in Italy as a threat to the Church and opposed him throughout.

Timeline

• 1215: Frederick II takes the cross at Aachen.
• 1227, 29 September: Gregory IX excommunicates Frederick.
• 1228, June: Frederick sails from Brindisi.
• 1228, September: Frederick arrives at Acre.
• 1229, 18 February: Treaty of Jaffa agreed with al-Kamil.
• 1229, 18 March: Frederick wears the crown in the Church of the Holy Sepulchre.
• 1229, 1 May: Frederick leaves Acre for Italy.
• 1244: Jerusalem is sacked by Khwarazmian forces.

Legacy

Christian rule in Jerusalem lasted only about fifteen years. In 1244 Khwarazmian troops in Ayyubid service sacked the city, and the Franks were crushed soon after at the Battle of La Forbie. Frederick’s crusade nevertheless became a famous example of a negotiated settlement in the age of holy war.

Why it matters

The Sixth Crusade showed that the crusader states and the Ayyubid sultans could reach practical agreements based on shared interests. It also exposed the deep conflict between the papacy and the emperor, which undermined crusading for decades.