In the mid-18th century, one Ibrahim al-Dimiati, perhaps a judge, was on a ship heading towards Crete. Close to its destination, it was captured by a Maltese vessel.

Dimiati was found to be carrying a bag containing several notebooks and a purse of 100 riyals. His captors took the money and threw the books back at him. (No, although I am a member of Umasa, the union of the university's academic staff, this is not a parable on academe.)

In Malta, Dimiati was taken before the man he calls "the tyrant of Malta", who, seeing Dimiati's books, ordered his release and gave instructions for him to be taken to a certain church. There, in Arabic, the captain of the ship told a "monk" that Dimiati was to be hosted until a ship arrived that could transport him back home.

A conversation ensued between Dimiati and the monk. The latter, it transpired, could read and write in Arabic. As a Christian boy, in Jerusalem, he had served a Muslim judge as a scribe and copyist, eventually advancing himself to the position of a judge. After his teacher died, he returned to his country, Malta, his luggage full of books.

During Dimiati's month-long stay in Malta, he and the monk became good friends. When Dimiati boarded the ship that was to take him back, "he gave me food from the best he had".

The full 18th century account given of Dimiati's story (together with that of another captive, the pregnant daughter of the Moroccan sultan Mulay Idris) may be found in Nabil Matar's recent publication, Europe Through Arab Eyes 1578-1727 (Columbia University Press).

If this tale - whose most exotic ingredient is perhaps the fluency with which Arabic appears to be spoken by some Maltese - rings strange to our ears it could be because our understanding of the historic relations between Christianity and Islam has been tuned up by developments a century later, during European colonialism.

This is the argument made by Jonathan Riley-Smith, who lectured here last week on the military orders during the mediaeval period, in his fascinating new book The Crusades, Christianity And Islam (Columbia University Press).

For Mr Riley-Smith, our contemporary understanding of the Crusades and their long aftermath (historians take the conventional demise of the crusading spirit to be 1798, that is, the Knights' loss of Malta to the French) has been deeply distorted by the 19th century, during which "the ideas and images [of crusading] were seized on and exploited to serve the ends of empire".

In 1889, the remarkable Archbishop of Algiers, Charles Lavigerie, a cardinal and confidant of Pope Leo XIII (who said, upon his death, that he had loved him as the apostle Peter had loved his brother Andrew), conceived a military order of missionaries in Africa - fortified asylums in the Sahara, placed on vital communication routes, with the additional purpose of "advancing commerce and civilisation".

He thought the Knights of Malta could serve as a model for such ordained "volunteers of civilisation and peace". The Knights themselves steered well clear of this project.

It was short-lived but the rhetoric was not. It was widespread and had various guises. The widely read novels of Sir Walter Scott, for example, imaginatively reconstructed the Crusades. The image of the Crusaders as cruder than their sophisticated civilised Muslim counterparts goes back to Scott, who had his own reasons for portraying Saladin as a precursor of the liberal gentleman.

Muslim Arabs themselves had not historically given much attention to the Crusades or to Saladin. They had won the wars and Saladin, a Kurd, was not the greatest of their generals or rulers. But Arab nationalists began to celebrate him increasingly - especially after, in 1898, with a nationalist agenda in mind, Kaiser Wilhelm II paid homage to Saladin in Jerusalem.

The dual theme of distorted self-images borrowed from one's adversaries is an important one in Mr Riley-Smith's account - whether they are Christian or Muslim self-images. As he shows, they are also important for an understanding of Malta's identity, as the Knights became increasingly aware of the anachronism of their vocation.

The Crusades, Mr Riley-Smith argues, were not waged out of economic interests but out of a certain penitential and ethical sense of a "common good" deemed to be of universal importance. To realise this is to see that we are not as cut off from their spirit as we might like to be. Such a spirit "has manifested itself recently in wars waged in the names of imperialism, nationalism, Marxism, fascism, anticolonialism, humanitarianism and even liberal democracy".

So things do not change, right? Wrong. In a month where so much of the world looks towards Jerusalem as a metaphor of peace and conflict, we do well to remember just how much depends on our political self-understanding. (And we could spare a thought on how much that, in its turn, depends on academic scholarship.)

ranierfsadni@europe.com