Were there RCatholic Cardinals at the Royal Wedding? Did the Vatican City have a dignitary present at wedding?

Cardinal Sean Brady, Cardinal Cormac Murphy O'Conner and Cardinal Keith O'Brien were all there. In addition the current Archbishop of Westminster, Vicent Nicholls, was there. Leaders or representatives of other churches and religious denominations were also present - Church of England, Church of Scotland, Presbyterian Church in Ireland, Salvation Army, various Jewish congregations and representatives of Muslim, Hindu, Jain and Zoroastrian communities, as well as some representatives of inter-church and interreligious groups. The Orthodox bishop you saw was probably Archbishop Gregorios, the Greek Orthodox Arcbhishop of Britain.