People affected by the events in London of 7th July 2005 gather in St Paul's Cathedral in the presence of Her Majesty the Queen and His Royal Highness the Duke of Edinburgh, to offer each other mutual support and remember those who died.
Invited guests include politicians and ambassadors from many countries, members of the emergency services, the police and London Transport.
Local clergy and representatives of many faiths will be there, as well as survivors and those who lost loved ones.
Nicholas Witchell comments on the service which is led by the Dean of St Paul's, the Very Rev'd Dr John Moses with the Bishop of London, the Rt Rev'd and Rt Hon Richard Chartres, the Archbishop of Westminster, His Eminence Cardinal Cormac Murphy-O'Connor and the Rev'd Esme Beswick, Co-President of Churches Together in England.
The service includes the symbolic lighting of candles as a memorial for those who died and who still suffer, and as a sign of a renewed commitment to work together for peace.
The sermon is preached by The Most Rev'd and Rt Hon Dr Rowan Williams, the Archbishop of Canterbury.
Cathedral Organist: Malcolm Archer; Sub-Organist: Huw Williams.