The crusaders believed their oaths were made invalid when the Byzantine contingent under Tatikios failed to help them during the siege of Antioch ; Bohemund, who had set himself up as Prince of Antioch, briefly went to war with Alexios in the Balkans, but was blockaded by the Byzantine forces and agreed to become Alexios ' vassal by the Treaty of Devol in 1108.

Alexios IV Angelos, the son of the deposed Isaac II, had recently escaped from Constantinople and now appealed to the crusaders, promising to end the schism of East and West, to pay for their transport, and to provide military support to the crusaders if they helped him to depose his uncle and sit on his father's throne.

The crusaders, whose objective had been Egypt, were persuaded to set their course for Constantinople before which they appeared in June 1203, proclaiming Alexios IV as Emperor and inviting the populace of the capital to depose his uncle.

The crusaders had wanted to conquer Egypt since the days of Baldwin I, who died during an expedition there.

The Fatimids, under the nominal rule of caliph al-Musta ' li but actually controlled by vizier al-Afdal Shahanshah, had lost Jerusalem to the Seljuqs in 1073 ; they recaptured it in 1098 from the Artuqids, a smaller Turkish tribe associated with the Seljuqs, just before the arrival of the crusaders.

John did accompany Frederick to the mainland, but Frederick was not well-received there ; one of his few supporters was Balian, Lord of Sidon, who had welcomed the crusaders the year before and now acted as an ambassador to the Ayyubids.

The crusaders may have been aware of the new divisions among the Ayyubids ; al-Kamil had occupied Damascus in 1238 but had died soon afterwards, and his territory was inherited by his family.

Along the way, Walter of Brienne captured livestock intended to resupply Damascus, as the Ayyubids had probably learned of the crusaders ' plans to attack it.

Damietta was captured without resistance when the crusaders landed in June 1249, but the crusade halted there until November, by which time the Egyptian sultan Ayyub had died and had been succeeded by his son Turanshah.

According to Ellenblum's interpretation the inhabitants of the Kingdom ( Latin Christians living alongside native Greek and Syrian Christians, Shia and Sunni Arabs, Sufis, Bedouin, Turks, Druze, Jews, and Samaritans ) all had major differences between each other as well as with the crusaders.

The Turks were the common enemy for everyone, as they were only very recent arrivals in the Levant, and although they had imposed their rule prior to the arrival of the crusaders, it is unlikely that they were thoroughly Islamicized as Prawer and others believed.

The crusaders were neither totally integrated with the native population, nor did they segregate themselves in the cities away from the rural natives, but rather that they settled in both urban and rural areas ; specifically, they settled in areas that had traditionally been inhabited by the eastern Christians.

The crusaders " had a natural tendency to ignore these matters as simply without interest and certainly not worthy of record.

Greeks, Syrians, and Jews continued to live as they had before, subject to their own laws and courts, with their former Muslim overlords simply replaced by the crusaders ; Muslims now joined them at the lowest level of society.

Jerusalem collected money through tribute payments, first from the coastal cities which had not yet been captured, and later from other neighbouring states such as Damascus and Egypt, which the crusaders could not conquer directly.

The last Estonian county to hold out against the invaders was the island county of Saaremaa, whose war fleets had raided Denmark and Sweden during the years of fighting against the German crusaders.

Innocent III declared that those who took the vow to become crusaders but could no longer perform the tasks that they had promised to complete, they could be released of their oaths by a contribution of funds to the original cause.

In 1224, after additional troops led by prince Vyachko of Kukenois had been installed in the fort, it was besieged and conquered for one last time by the German crusaders.

These men, who had gone to Palestine from Europe either as pilgrims or as crusaders, chose Mount Carmel in part because it was the traditional home of Elijah.

He shared the poor opinion of Alexius I Comnenus that had developed during the First Crusade, although he was also critical of some of the crusaders ' dealings with Alexius.

By mid 1209, around 10, 000 crusaders had gathered in Lyon before marching south.

The crusaders had taken Belcaire and besieged Marmande in late 1218 under Amaury de Montfort, son of the late Simon.

Adhemar negotiated with Alexius I Comnenus at Constantinople, reestablished at Nicaea some discipline among the crusaders, fought a crucial role at the Battle of Dorylaeum and was largely responsible for sustaining morale during the siege of Antioch through various religious rites including fasting and special observances of holy days.

The crusade came to an end peacefully, with the Treaty of Ramla negotiated in 1192 ; Saladin allowed pilgrimages to be made to Jerusalem, allowing the crusaders to fulfill their vows, after which they all returned home.

However, Nur ad-Din sent ambassadors and negotiated an alliance with the emperor against the Seljuks, much to the crusaders ' dismay.

When the populace rebelled in late January 1204, the emperors barricaded themselves in the palace and entrusted Alexios Doukas with a mission to seek help from the crusaders.

As powerful warriors serving the Muslim rulers of Damascus against the Crusades, the Druze were given the task of keeping watch over the crusaders in the seaport of Beirut, with the aim of preventing them from making any encroachments inland.

The purpose of the citadel was to prevent the Old Prussian settlement of Truso from being reoccupied, as the German crusaders were at war with the pagan Prussians.

The new kingdom, and Godfrey's reputation, was secured with the defeat of the Fatimid Egyptian army under al-Afdal Shahanshah at the Battle of Ascalon one month after the conquest, on August 12, but Raymond and Godfrey's continued antagonism prevented the crusaders from taking control of Ascalon itself.

The crusaders and their descendants often learned to speak Greek, Arabic, and other eastern languages, and intermarried with the native Christians ( whether Greek, Syrian, or Armenian ) and sometimes with converted Muslims.

Prawer argued further that the kingdom was an early attempt at colonization, in which the crusaders were a small ruling class, who were dependent on the native population for survival but made no attempt to integrate with them.

Although the crusaders came upon an ancient urban society, Ellenblum argues that they neither completely abandoned their rural European lifestyle, nor was European society completely rural to begin with.

The Chronicle of Henry of Livonia from the 1220s gives a firsthand account of the Christianization of Livonia, granted as a fief by the Hohenstaufen Holy Roman Emperor, de facto but not known as the King of Germany, Philip of Swabia, to Bishop Albert of Buxthoeven, nephew of the Hartwig II, Archbishop of Bremen, who sailed with a convoy of ships filled with armed crusaders to carve out a Catholic territory in the east during the Livonian Crusade.

The campaign continued in 1209 with an attack on the Orthodox Principality of Jersika ( known as Lettia ), accused by crusaders of being in alliance with Lithuanian pagans.

After Albert's death in 1229, the crusaders secured the peaceful submission of Vanemane ( a county with a mixed Livonian, Oselian, and Curonian population in the northeastern part of Courland ) by treaty in 1230.

In 1107 Sigurd I of Norway sailed for the eastern Mediterranean with a host of Norwegian crusaders to fight for the newly established Kingdom of Jerusalem, and the Danes and Swedes participated energetically in the Baltic Crusades of the 12th and 13th centuries.

Sigismund personally led an army of almost 50, 000 " crusaders " against the Croats and Bosnians, which culminated in 1408 with the Battle of Dobor, and a massacre of about 200 noble families, many of them victors of numerous battles against the Ottomans.

* The town of Riga is chartered as a city by Bishop Albert, who landed on the site of the town with 1, 500 crusaders earlier that year.

Added to this was a long struggle to expel the Moors that was religiously sanctioned and influenced by foreign crusaders with a desire for martial fame.

The Fatimids, under the nominal rule of caliph al-Musta ' li but actually controlled by vizier al-Afdal Shahanshah, had lost Jerusalem to the Seljuqs in 1073 ( although some older accounts say 1076 ); they recaptured it in 1098 from the Artuqids, a smaller Turkish tribe associated with the Seljuqs, just before the arrival of the crusaders.

On 7 May 1099 the crusaders reached Jerusalem, which had been recaptured from the Seljuks by the Fatimids of Egypt only a year before.

Fatimids had attempted to make peace, on the condition that the crusaders not continue towards Jerusalem, but this was ignored ; Iftikhar ad-Daula, the Fatimid governor of Jerusalem, was aware of the Crusaders ' intentions.

On 7 June, the crusaders reached Jerusalem, which had been recaptured from the Seljuqs by the Fatimids only the year before.

The Fatimids, assuming the crusaders were simply mercenary representatives of the Byzantines, were prepared to let the crusaders keep Syria if they agreed not to attack Fatimid Palestine, a state of affairs perfectly acceptable between Egypt and Byzantium before the Turkish invasions.

Jerusalem was captured from the Fatimids on July 15, 1099, after a long siege, and immediately the crusaders learned that a Fatimid army was on its way to besiege them.

According to captives taken by Tancred in a skirmish near Ramla, the animals were there to encourage the crusaders to disperse and pillage the land, making it easier for the Fatimids to attack.

The crusaders spent the night in the abandoned camp, preparing for another attack, but in the morning they learned that the Fatimids were retreating to Egypt.

Artuq died in 1091, and his sons Sokman and Ilghazi were expelled from Jerusalem by the Fatimid vizier al-Afdal Shahanshah in 1098 ; the Fatimids lost the city to the crusaders the following year.