The Crusades are seen by many Muslims as acts of violence that have underpinned Western aggression towards the Arab world ever since. Followers of Osama bin Laden claim to be taking part in a latter-day “jihad against the Jews and Crusaders”.

The late Pope John Paul II sought to achieve Muslim- Christian reconciliation by asking “pardon” for the Crusades during the 2000 Millennium celebrations. But John Paul’s apologies for the past “errors of the Church” — including the Inquisition and anti-Semitism — irritated some Vatican conservatives. According to Vatican insiders, the dissenters included Cardinal Joseph Ratzinger, now Pope Benedict XVI.

Pope Benedict reached out to Muslims and Jews after his election and called for dialogue. However, the Pope, who is due to visit Turkey in November, has in the past suggested that Turkey’s Muslim culture is at variance with Europe’s Christian roots.

At the conference, held at the Regina Apostolorum Pontifical University, Roberto De Mattei, an Italian historian, recalled that the Crusades were “a response to the Muslim invasion of Christian lands and the Muslim devastation of the Holy Places”.

“The debate has been reopened,” La Stampa said. Professor De Mattei noted that the desecration of the Holy Sepulchre in Jerusalem by Muslim forces in 1009 had helped to provoke the First Crusade at the end of the 11th century, called by Pope Urban II.

He said that the Crusaders were “martyrs” who had “sacrificed their lives for the faith”. He was backed by Jonathan Riley-Smith, Dixie Professor of Ecclesiastical History at Cambridge University, who said that those who sought forgiveness for the Crusades “do not know their history”. Professor Riley-Smith has attacked Sir Ridley Scott’s recent film Kingdom of Heaven, starring Orlando Bloom, as “utter nonsense”.

Professor Riley-Smith said that the script, like much writing on the Crusades, was “historically inaccurate. It depicts the Muslims as civilised and the Crusaders as barbarians. It has nothing to do with reality.” It fuels Islamic fundamentalism by propagating “Osama bin Laden’s version of history”.

He said that the Crusaders were sometimes undisciplined and capable of acts of great cruelty. But the same was true of Muslims and of troops in “all ideological wars”. Some of the Crusaders’ worst excesses were against Orthodox Christians or heretics — as in the sack of Constantinople in 1204.

The American writer Robert Spencer, author of A Politically Incorrect Guide to Islam, told the conference that the mistaken view had taken hold in the West as well as the Arab world that the Crusades were “an unprovoked attack by Europe on the Islamic world”. In reality, however, Christians had been persecuted after the Muslim conquest of Jerusalem.

CONFLICT OVER THE HOLY LAND