What caused conflict leading up to the First Crusade?

The Crusades were a series of religious wars between Christians and Muslims started primarily to secure control of holy sites considered sacred by both groups. In all, eight major Crusade expeditions occurred between 1096 and 1291. The bloody, violent and often ruthless conflicts propelled the status of European Christians, making them major players in the fight for land in the Middle East. By the end of the 11th century, Western Europe had emerged as a significant power in its own right, though it still lagged behind other Mediterranean civilizations, such as that of the Byzantine Empire (formerly the eastern half of the Roman Empire) and the Islamic Empire of the Middle East and North Africa.
However, Byzantium had lost considerable territory to the invading Seljuk Turks. After years of chaos and civil war, the general Alexius Comnenus seized the Byzantine throne in 1081 and consolidated control over the remaining empire as Emperor Alexius I. In 1095, Alexius sent envoys to Pope Urban II asking for mercenary troops from the West to help confront the Turkish threat. Though relations between Christians in the East and West had long been fractious, Alexius’s request came at a time when the situation was improving.
In November 1095, at the Council of Clermont in southern France, the Pope called on Western Christians to take up arms to aid the Byzantines and recapture the Holy Land from Muslim control. This marked the beginning of the Crusades.
Pope Urban’s plea was met with a tremendous response, both among the military elite as well as ordinary citizens. Those who joined the armed pilgrimage wore a cross as a symbol of the Church.
The Crusades set the stage for several religious knightly military orders, including the Knights Templar, the Teutonic Knights, and the Hospitallers. These groups defended the Holy Land and protected pilgrims traveling to and from the region. Did you know? In a popular movement known as the Children's Crusade (1212), a motley crew including children, adolescents, women, the elderly and the poor marched all the way from the Rhineland to Italy behind a young man named Nicholas, who said he had received divine instruction to march toward the Holy Land Four armies of Crusaders were formed from troops of different Western European regions, led by Raymond of Saint-Gilles, Godfrey of Bouillon, Hugh of Vermandois and Bohemond of Taranto (with his nephew Tancred). These groups departed for Byzantium in August 1096.
A less organized band of knights and commoners known as the “People’s Crusade” set off before the others under the command of a popular preacher known as Peter the Hermit.
Ignoring Alexius’ advice to wait for the rest of the Crusaders, Peter’s army crossed the Bosporus in early August. In the first major clash between the Crusaders and Muslims, Turkish forces crushed the invading Europeans at Cibotus.
Another group of Crusaders, led by the notorious Count Emicho, carried out a series of massacres of Jews in various towns in the Rhineland in 1096, drawing widespread outrage and causing a major crisis in Jewish-Christian relations.
When the four main armies of Crusaders arrived in Constantinople, Alexius insisted that their leaders swear an oath of loyalty to him and recognize his authority over any land regained from the Turks, as well as any other territory they might conquer. All but Bohemond resisted taking the oath.
In May 1097, the Crusaders and their Byzantine allies attacked Nicea (now Iznik, Turkey), the Seljuk capital in Anatolia. The city surrendered in late June. Despite deteriorating relations between the Crusaders and Byzantine leaders, the combined force continued its march through Anatolia, capturing the great Syrian city of Antioch in June 1098.
After various internal struggles over control of Antioch, the Crusaders began their march toward Jerusalem, then occupied by Egyptian Fatimids (who as Shi’ite Muslims were enemies of the Sunni Seljuks).
Encamping before Jerusalem in June 1099, the Christians forced the besieged city’s governor to surrender by mid-July.
Despite Tancred’s promise of protection, the Crusaders slaughtered hundreds of men, women, and children in their victorious entrance into Jerusalem

The biggest effect of Bacon's Rebellion was that labor in Virginia and neighboring Colonies turned away from using indentured servants and began to invest in slavery instead.