Even though Islam and Christianity represented by Europe have many areas of commonality and a shared monotheistic origin, their relationship has been marred by confrontation rather than understanding and dialogue.

From the earliest decades of Islamic history, Christianity and Islam have been locked in a political and theological struggle, because Islam, unlike other world religions, has threatened the political and religious ascendancy of Christianity.^[34]

Islam's fast growth including substantial conversions of Christians in 11^th century, the grandeur of its power and civilisation in comparison to a stagnated Christian Europe struggling through its Dark Ages triggered a hostile response towards Islam. While Dante's Divine Comedy sent off Muhammad to the lowest level of hell, Islam was depicted as a religion spread by the sword and Muhammad was vilified as an 'infidel imposter', who was the 'anti-Christ'.

The turning point was the victory of the Seljuq Turkish army over the Byzantine army in 1071 that resulted in the loss of Asia Minor (where present-day Turkey is situated). This led a call to Christian Europe to unite under the flag of Christianity and liberate the holy city of Jerusalem, triggering a series of Crusades that lasted till 1453.

The contrast between the behaviour of the Christian and Muslim armies in the first crusade has been etched deeply in the collective memory of Muslims. In 1099, the Crusaders stormed Jerusalem and established Christian sovereignty over the Holy Land. They left no Muslim survivors; women and children were massacred. The Noble Sanctuary, the Haram al-Sharif, was desecrated as the Dome of the Rock was converted into a church and the al-Aqsa mosque, renamed the Temple of Solomon, became a residence for the king In 1187, Salah al-Din (Saladin) led his army in a fierce battle and recaptured Jerusalem. The Muslim army was as magnanimous in victory, as it had been tenacious in battle. Civilians were spared while churches and shrines were generally left untouched. The striking difference in military conduct were epitomised by the two dominant figures of the Crusades: Saladin and Richard the Lion-Hearted. The chivalrous Saladin was faithful to his word and compassionate towards non-combatants. Richard accepted the surrender of Acre and then proceeded to massacre all its inhabitants including women and children despite promises to the contrary.^[35]

Contrary to myths in Western perceptions, the Crusades did not achieve their goal of uniting Christian Europe and liberating Jerusalem. It certainly did not halt Islam's growth. On the contrary, Middle Eastern minority populations converted to Islam under the poor governance of Christian rulers. Jerusalem was under Muslim rule majority of the time, while the Ottomans carried Islam to mainland Europe. The fall of Constantinople (Istanbul) to Ottomans in 1453 brought an end to the Crusades leaving in its midst a deeply divided Europe.

[34] Esposito, John L, "Islam the Straight Path", Oxford University Press, 1998, p 57
[35] Esposito, John L, "Islam the Straight Path", Oxford University Press,1998, p 59