The Royal Commission on the Ancient and Historic Monuments of Wales and Monmouthshire was established by Royal Warrant in 1908, to make an inventory of ancient and historical monuments and to specify those that were worthy of preservation. It was renamed the Royal Commission on the Ancient and Historic Monuments of Wales (RCAHMW) in 1974.
The Royal Warrant sets out the purposes and powers of RCAHMW, namely to provide for the survey and recording of ancient and historical monuments and constructions connected with, or illustrative of, the contemporary culture, civilisation and conditions of life of the people in Wales from the earliest times (including the ancient and historical monuments and constructions in, on or under, the sea bed within the United Kingdom territorial sea adjacent to Wales). This is to be done by:
- compiling, maintaining and curating the National Monuments Record of Wales as the basic national record of the archaeological and historical environment;
- identifying, surveying, interpreting and recording all buildings, sites and ancient monuments of archaeological, architectural and historic interest in Wales or within the territorial sea adjacent to Wales, in order both to enhance and update the National Monuments Record of Wales;
- providing advice and information relevant to the preservation and conservation of such buildings, sites and ancient monuments of archaeological, architectural and historic interest;
- collecting and exchanging data with other record holders and providing an index to data from other sources;
- promoting the public use of information available in the National Monuments Record of Wales by all appropriate means;
- establishing and maintaining national standards in surveying, recording and curating of records relating to archaeology and historical architecture and providing guidance on these matters to other bodies;
- exercising responsibility for the oversight of local Sites and Monuments Records.