That cathedrals survived the Reformation at all is something that Anglicans, not least those of the Church of Ireland, have rather taken for granted. They might easily have gone the way of the monasteries, those other semi-autonomous ecclesiastical corporations that they so closely resembled.

This point was made by Patrick Collinson, Regius Professor of History at the University of Cambridge, when some 5 1/2 years ago he inaugurated the Christ Church history project. The fact that, unusually, Dublin since medieval times has had two cathedrals makes the survival of both of them even more remarkable.

Why Christ Church survived (and, at times, how tenuously) is the tale told in our History. It is a story rooted in the Danish kingdom of Dublin and covers the cathedral's centuries as an Augustinian priory bringing us down the ages to our own day. One 17th-century visitor described Christ Church as "where the government comes to church", and so it was, fiercely clinging to its post-Reformation role as chapel royal as well as cathedral.

Indeed it clung tenaciously to all its prerogatives in the face of challenges, not least from the very city with which at times it had a love-hate relationship. For the dean and chapter of Christ Church not only ruled the cathedral. They also claimed manorial jurisdiction over Dubliners' "liberty" which led at times to unseemly tussles for control.

But the secular power had the last word, and with the disestablishment and disendowment of the Church of Ireland in the late 19th century Christ Church found itself in a drastically changed situation. Its prestige was diminished, and impoverishment stared it in the face. As though that were not sufficient cause for alarm, within 50 years of disestablishment the very nature of the State itself changed, as the 26 counties achieved virtual independence.

However, the Church of Ireland's leadership at the time of the inception of the Irish Free State was pragmatic, and a succession of deans saw it as their duty to lead Christ Church from its pre-disestablishment role as a well-endowed, largely self-regulating institution, to one that was increasingly dependent on the goodwill and generosity of the people of the parishes and, indeed, of the city of Dublin in general and its growing number of visitors.

Christ Church survived the Reformation. Would it also survive the impact of the religious and intellectual changes in late-20th-century Ireland, or would cathedrals be left rather like beached whales as the tide of faith receded? Surprisingly, rather than finding themselves obsolescent, cathedrals are discovering a new role.

As well as providing a ministry for their regular congregations they are seeking to offer, however tentatively, a ministry to the great numbers of people who come to visit them from home and abroad. Regarding these visitors not so much as tourists but pilgrims, cathedrals seek to emphasise that they are not museums, but that their architecture, liturgy and music, which exercise an increasing attraction, particularly for young people, are part of an ongoing life of Christian worship and witness.

The hope is that visitors will sense something of the religious spirit that caused earlier generations to found such places. But many visitors do not come to pray, and may well ask "Why worship?" That is the theme of Ceiliuradh, an international and ecumenical conference and festival of liturgy that yesterday was officially opened at Christ Church by the President of Ireland, Mrs McAleese.

Even those who habitually worship feel the need to reflect, in a changing culture, on the meaning and purpose of what they are doing. Some regular worshippers want to experiment with new forms of worship, while at the same time cherishing the different liturgical traditions that they have inherited.

Ceiliuradh will therefore introduce us to new expressions of worship; but it will also provide, on Thursday, a "day of offices" when members of religious communities from different parts of Ireland will come to Christ Church to lead us in the singing of those ageless "hours" that lie at the heart of their religious life.

For Anglicans they are perpetuated in the orders for Morning and Evening Prayer and Compline.

The history of an institution such as Christ Church Cathedral is not consistently edifying. There is indeed much that tells of devotion to God and Christian charity, but there is also much that speaks of human frailty, greed and prejudice. Yet we believe it to be a tale worth telling, and trust that readers will find in our pages something to illuminate their perception of this cathedral and of the city in which it is set.

Dr Kenneth Milne is Church of Ireland Historiographer and general editor of Christ Church Cathedral, Dublin: A History (Four Courts Press, £30). Ceiliuradh, an international celebration of Christian liturgy, concludes at Christ Church Cathedral this coming Friday (June 23rd).