National service of thanksgiving
A national service of thanksgiving in the United Kingdom is an act of Christian worship, generally attended by the British monarch, Great Officers of State and Ministers of the Crown, which celebrates an event of national importance. Originally it started with the intention to give thanks for victory in battle. However it evolved to celebrate occasions such as a royal jubilee, a royal wedding anniversary, or the end of a conflict. These services are usually held at St Paul's Cathedral in the City of London.